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diff --git a/docs/source/hardware/maple.rst b/docs/source/hardware/maple.rst new file mode 100644 index 0000000..b187115 --- /dev/null +++ b/docs/source/hardware/maple.rst @@ -0,0 +1,618 @@ +.. highlight:: sh + +.. _maple: + +Maple +===== + +This page is a general resource for information specific to the Maple. + +.. contents:: Contents + :local: + +.. TODO [dma.rst] Ref to dma.rst in sequel instead of libmaple-dma +.. TODO [nvic.rst] Ref to nvic.rst in sequel + +Technical Specifications +------------------------ + +* MCU: :ref:`STM32F103RBT6 <maple-stdocs>`, a 32-bit ARM Cortex M3 + microprocessor +* Clock Speed: **72 MHz** +* **128 KB Flash** and **20 KB SRAM** +* 43 :ref:`digital I/O pins (GPIOs) <gpio>` +* 15 :ref:`PWM <pwm>` pins at 16 bit resolution +* 15 :ref:`analog input (ADC) <adc>` pins at 12-bit resolution +* 2 :ref:`SPI <spi>` peripherals +* 2 :ref:`I2C <i2c>` peripherals +* 7 Channels of Direct Memory Access (**DMA**) (:ref:`libmaple-dma`) +* 3 :ref:`USART (serial port) <usart>` peripherals +* One advanced and three general-purpose :ref:`timers <timers>` +* Dedicated :ref:`USB <usb>` port for programming and communications +* :ref:`JTAG <jtag>` +* Nested Vectored Interrupt Controller (NVIC) (including + :ref:`external interrupt <external-interrupts>` on GPIOs) +* Supplies up to 500 mA at 3.3 V, with separate 250 mA digital and + analog regulators for low-noise analog performance +* :ref:`Open source, four layer design <maple-hardware>` +* Support for low power, sleep, and standby modes (<500 μA) +* Operating Voltage: 3.3 V +* Input Voltage (recommended): 4 V — 12 V +* Dimensions: 2.05″ × 2.1″ + +.. _maple-identify-rev: + +Identifying your Rev +-------------------- + +We went through three versions ("Revs") of the Maple hardware: Rev 1, +Rev 3, and Rev 5 [#frev2_4]_; Rev 5, the final design, is currently on +sale. The following sections will help you to help you identify your +Rev. + +Rev 5 +^^^^^ + +These boards went on sale in November 2010. They have white buttons +and "r5" in small print near the "LeafLabs Maple" text next to the +"infinity leaf" logo. The Maple Rev 5 repositioned the double header +on the right hand side to better fit 0.1 inch pitch breadboard. This +necessitated the removal of pins 21 and 22 from the double header; +they are still available, but don't have any headers installed on +them. + +.. figure:: /_static/img/maple_rev5.png + :align: center + :alt: Maple Rev 5 + +Rev 3 +^^^^^ + +This batch of boards went on sale beginning in May 2010. They have a +darker red silkscreen and the "infinity leaf" logo. The Maple Rev 3 +was the first version which includes the built-in button, labeled BUT. + +.. figure:: /_static/img/maple_rev3.png + :align: center + :alt: Maple Rev 3 + +Rev 1 +^^^^^ + +A small number of Maple Rev 1 boards went on sale in late 2009. They +have a light red silkscreen and a single pixelated leaf as a logo. + +.. figure:: /_static/img/maple_rev1.png + :align: center + :alt: Maple Rev 1 + +.. _maple-powering: + +Powering the Maple +------------------ + +The Maple's power source is determined by the header to the left of +the "LeafLabs" label on the silkscreen. All versions of the Maple can +be powered from the barrel jack connector, USB, or a LiPo battery. We +ship the Maple with a jumper on the USB selector. In order to power +it off of an alternative source, unplug the Maple, then move the +jumper to the desired selector before reconnecting power. + +You can also power the Maple via the pin labeled "Vin" on the lower +header. This pin feeds into both the digital and analog voltage +regulators. However, don't do this while simultaneously powering the +board from another source, or you could damage it. + +When powering the board from a barrel jack, **double check the +polarity of the barrel.** The appropriate polarity is noted on the +silkscreen right next to the connector. + +.. warning:: Silkscreens on Maples up through Rev 5s manufactured in + Spring 2011 falsely indicated that the barrel jack could be + supplied by up to 18V. (Rev5s manufactured after Spring 2011 may + still have this error on the silk, but it has been marked over.) We + recommend a barrel jack input voltage **no greater than 12V**, and + potentially even lower depending upon the current draw requirements + of the application. The same goes for powering off LiPo batteries. + + Please see :ref:`Power Regulation on the Maple + <maple-power-regulation>` for more information. + +.. _maple-power-regulation: + +Power Regulation on the Maple +----------------------------- + +Power regulation on the Maple is provided by two low dropout linear +voltage regulators. (The part is the MCP1703 from Microchip, in the +SOT-23A package. You can download the datasheet `here +<http://ww1.microchip.com/downloads/en/DeviceDoc/22049a.pdf>`_ ). One +of the regulators supplies power to the digital voltage plane; the +other supplies power to the analog voltage plane. + +These voltage regulators nominally take an input of up to 16V. In +addition, while the maximum continuous output current for the board is +250mA, if you are powering the board off higher voltages the current +it can supply goes down, due to the regulators needing to dissipate +the extra power. So if you are powering the board off 12V, the max +current is about 40mA at room temperature. In general (again, at room +temperature) the max power dissipation (PD) for the chip is about +.37W, and output current = PD/(Vin-Vout). For exact max current +calculations, please refer to the datasheet linked above. + +If you are planning to draw a lot of current from the Maple board, it +is necessary to provide input power as close to 3.3V as +possible. Powering the microcontroller circuitry and LEDs on the board +alone takes approximately 30mA, so if you are powering the board with +12V that leaves only 10mA (at best) available for powering any user +circuitry. Attempting to draw more than 10mA runs the risk of shorting +out the power regulators and bricking your board. + +Using the Built-in Battery Charger +---------------------------------- + +Maples Rev 3 and Rev 5 also have a built-in LiPo battery charger. In +order to use it, put a jumper across the CHRG header on the power +selection header and across the USB, or EXT selectors, depending on +whether you're charging the battery via USB cable or barrel jack +connector. The LED labeled CHRG will light up while the battery is +being charged. When the battery is finished charging, the LED labeled +DONE will light up. + +.. _maple-gpios: + +GPIO Information +---------------- + +The Maple features 38 ready-to-use general purpose input/output (see +:ref:`gpio`) pins for digital input/output, numbered ``D0`` through +``D37``. These numbers correspond to the numeric values next to each +header on the Maple silkscreen. + +.. _maple-ret6-but: + +Pin ``D38`` is the board's :ref:`button pin <lang-board-values-but>`. +It is thus mainly useful as an :ref:`input <lang-pin-levels>`. The +pin will :ref:`read <lang-digitalread>` ``HIGH`` when the :ref:`button +is pressed <lang-isbuttonpressed>`. + +More GPIOs (numbered ``D39``\ --``D42`` on the back of the Maple's +silkscreen) are available if you use the :ref:`lang-disabledebugports` +function; see the :ref:`board-specific debug pin constants +<lang-board-values-debug>` for more information. (See :ref:`this +erratum <maple-nrst-pb4>` for information about the pin numbered +``43`` on the silkscreen). + +.. TODO [0.1.0] silkscreen pictures which expand abbreviations + +.. _maple-pin-map-master: + +Master Pin Map +^^^^^^^^^^^^^^ + +This table shows a summary of the available functionality on every +GPIO pin, by peripheral type. The "5 V?" column documents whether or +not the pin is :ref:`5 volt tolerant <gpio-5v-tolerant>`. + +Note that this table is not exhaustive; on some pins, more peripherals +are available than are listed here. + +.. csv-table:: + :header: Pin, :ref:`GPIO <gpio>`, :ref:`ADC <adc>`, :ref:`Timer <timers>`, :ref:`I2C <i2c>`, :ref:`UART <usart>`, :ref:`SPI <spi>`, 5 V? + + D0, PA3, CH3, 2_CH4, -, 2_RX, -, - + D1, PA2, CH2, 2_CH3, -, 2_TX, -, - + D2, PA0, CH0, 2_CH1_ETR, -, 2_CTS, -, - + D3, PA1, CH1, 2_CH2, -, 2_RTS, -, - + D4, PB5, -, -, 1_SMBA, -, -, - + D5, PB6, -, 4_CH1, 1_SCL, -, -, Yes + D6, PA8, -, 1_CH1, -, 1_CK, -, Yes + D7, PA9, -, 1_CH2, -, 1_TX, -, Yes + D8, PA10, -, 1_CH3, -, 1_RX, -, Yes + D9, PB7, -, 4_CH2, 1_SDA, -, -, Yes + D10, PA4, CH4, -, -, 2_CK, 1_NSS, - + D11, PA7, CH7, 3_CH2, -, -, 1_MOSI, - + D12, PA6, CH6, 3_CH1, -, -, 1_MISO, - + D13, PA5, CH5, -, -, -, 1_SCK, - + D14, PB8, -, 4_CH3, -, -, -, Yes + D15, PC0, CH10, -, -, -, -, - + D16, PC1, CH11, -, -, -, -, - + D17, PC2, CH12, -, -, -, -, - + D18, PC3, CH13, -, -, -, -, - + D19, PC4, CH14, -, -, -, -, - + D20, PC5, CH15, -, -, -, -, - + D21, PC13, -, -, -, -, -, - + D22, PC14, -, -, -, -, -, - + D23, PC15, -, -, -, -, -, - + D24, PB9, -, 4_CH4, -, -, -, Yes + D25, PD2, -, 3_ETR, -, -, -, Yes + D26, PC10, -, -, -, -, -, Yes + D27, PB0, CH8, 3_CH3, -, -, -, - + D28, PB1, CH9, 3_CH4, -, -, -, - + D29, PB10, -, -, 2_SCL, 3_TX, -, Yes + D30, PB11, -, -, 2_SDA, 3_RX, -, Yes + D31, PB12, -, -, 2_SMBA, 3_CK, 2_NSS, Yes + D32, PB13, -, -, -, 3_CTS, 2_SCK, Yes + D33, PB14, -, -, -, 3_RTS, 2_MISO, Yes + D34, PB15, -, -, -, -, 2_MOSI, Yes + D35, PC6, -, -, -, -, -, Yes + D36, PC7, -, -, -, -, -, Yes + D37, PC8, -, -, -, -, -, Yes + D38, PC9, -, -, -, -, -, Yes + D39, PA13, -, -, -, -, -, Yes + D40, PA14, -, -, -, -, -, Yes + D41, PA15, -, -, -, -, -, Yes + D42, PB3, -, -, -, -, -, Yes + +.. _maple-gpio-port-map: + +GPIO Port Pin Map +^^^^^^^^^^^^^^^^^ + +The following table shows what pins are associated with each +:ref:`GPIO port <gpio-ports>`. + +.. csv-table:: + :header: GPIOA, GPIOB, GPIOC + + PA0: D2, PB0: D27, PC0: D15 + PA1: D3, PB1: D28, PC1: D16 + PA2: D1, PB2: -, PC2: D17 + PA3: D0, PB3: D42, PC3: D18 + PA4: D10, PB4: D43, PC4: D19 + PA5: D13, PB5: D4, PC5: D20 + PA6: D12, PB6: D5, PC6: D35 + PA7: D11, PB7: D9, PC7: D36 + PA8: D6, PB8: D14, PC8: D37 + PA9: D7, PB9: D24, PC9: D38 + PA10: D8, PB10: D29, PC10: D26 + PA11: -, PB11: D30, PC11: - + PA12: -, PB12: D31, PC12: - + PA13: D39, PB13: D32, PC13: D21 + PA14: D40, PB14: D33, PC14: D22 + PA15: D41, PB15: D34, PC15: D23 + +.. _maple-timer-map: + +Timer Pin Map +^^^^^^^^^^^^^ + +The following table shows what pins are associated with a particular +timer's capture/compare channels. + +.. csv-table:: + :header: Timer, Ch. 1, Ch. 2, Ch. 3, Ch. 4 + :delim: | + + 1 | D6 | D7 | D8 | - + 2 | D2 | D3 | D1 | D0 + 3 | D12 | D11 | D27 | D28 + 4 | D5 | D9 | D14 | D24 + +.. _maple-exti-map: + +EXTI Line Pin Map +^^^^^^^^^^^^^^^^^ + +The following table shows which pins connect to which :ref:`EXTI lines +<external-interrupts-exti-line>` on the Maple. + +.. list-table:: + :widths: 1 1 + :header-rows: 1 + + * - EXTI Line + - Pins + * - EXTI0 + - D2, D15, D27 + * - EXTI1 + - D3, D16, D28 + * - EXTI2 + - D1, D17, D25 + * - EXTI3 + - D0, D18, D42 + * - EXTI4 + - D10, D19 + * - EXTI5 + - D4, D13, D20 + * - EXTI6 + - D5, D12, D35 + * - EXTI7 + - D9, D11, D36 + * - EXTI8 + - D6, D14, D37 + * - EXTI9 + - D7, D24, D38 + * - EXTI10 + - D8, D26, D29 + * - EXTI11 + - D30 + * - EXTI12 + - D31 + * - EXTI13 + - D21, D32, D39 + * - EXTI14 + - D22, D33, D40 + * - EXTI15 + - D23, D34, D41 + +.. _maple-usart-map: + +USART Pin Map +^^^^^^^^^^^^^ + +The Maple has three serial ports (also known as :ref:`USARTs +<usart>`): ``Serial1``, ``Serial2``, and ``Serial3``. They communicate +using the pins given in the following table. + +.. csv-table:: + :header: Serial Port, TX, RX, CK, CTS, RTS + :delim: | + + ``Serial1`` | D7 | D8 | D6 | | + ``Serial2`` | D1 | D0 | D10 | D2 | D3 + ``Serial3`` | D29 | D30 | D31 | D32 | D33 + +.. _maple-adc-bank: + +Low-Noise ADC Pins +^^^^^^^^^^^^^^^^^^ + +The six pins at the bottom right of the board (D15—D20) generally +offer lower-noise ADC performance than other pins on the board. If +you’re concerned about getting good ADC readings, we recommend using +one of these pins to take your measurements. + +Maple has an electrically isolated analog power plane with its own +regulator, and a geometrically isolated ground plane. Pins D15—D20 are +laid out to correspond with these analog planes, and our measurements +indicate that they generally have the lowest noise of all the analog +lines. However, analog performance may vary depending upon the +activity of the other GPIOs. Consult the :ref:`Maple hardware design +files <maple-hardware>` for more details. + +Board-Specific Values +--------------------- + +This section lists the Maple's :ref:`board-specific values +<lang-board-values>`. + +- ``CYCLES_PER_MICROSECOND``: 72 +- ``BOARD_BUTTON_PIN``: 38 +- ``BOARD_LED_PIN``: 13 +- ``BOARD_NR_GPIO_PINS``: 44 (however, :ref:`pin D43 is not usable + <maple-nrst-pb4>`) +- ``BOARD_NR_PWM_PINS``: 15 +- ``boardPWMPins``: 0, 1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 14, 24, 27, 28 +- ``BOARD_NR_ADC_PINS``: 15 +- ``boardADCPins``: 0, 1, 2, 3, 10, 11, 12, 15, 16, 17, 18, 19, 20, 27, 28 +- ``BOARD_NR_USED_PINS``: 7 +- ``boardUsedPins``: ``BOARD_LED_PIN``, ``BOARD_BUTTON_PIN``, + ``BOARD_JTMS_SWDIO_PIN``, ``BOARD_JTCK_SWCLK_PIN``, + ``BOARD_JTDI_PIN``, ``BOARD_JTDO_PIN``, ``BOARD_NJTRST_PIN`` +- ``BOARD_NR_USARTS``: 3 +- ``BOARD_USART1_TX_PIN``: 7 +- ``BOARD_USART1_RX_PIN``: 8 +- ``BOARD_USART2_TX_PIN``: 1 +- ``BOARD_USART2_RX_PIN``: 0 +- ``BOARD_USART3_TX_PIN``: 29 +- ``BOARD_USART3_RX_PIN``: 30 +- ``BOARD_NR_SPI``: 2 +- ``BOARD_SPI1_NSS_PIN``: 10 +- ``BOARD_SPI1_MOSI_PIN``: 11 +- ``BOARD_SPI1_MISO_PIN``: 12 +- ``BOARD_SPI1_SCK_PIN``: 13 +- ``BOARD_SPI2_NSS_PIN``: 31 +- ``BOARD_SPI2_MOSI_PIN``: 34 +- ``BOARD_SPI2_MISO_PIN``: 33 +- ``BOARD_SPI2_SCK_PIN``: 32 +- ``BOARD_JTMS_SWDIO_PIN``: 39 +- ``BOARD_JTCK_SWCLK_PIN``: 40 +- ``BOARD_JTDI_PIN``: 41 +- ``BOARD_JTDO_PIN``: 42 +- ``BOARD_NJTRST_PIN``: :ref:`43 <maple-nrst-pb4>` + +.. _maple-hardware: + +Hardware Design Files +--------------------- + +The hardware schematics and board layout files are available in the +`Maple GitHub repository <https://github.com/leaflabs/maple>`_. The +design files for Rev 1, Rev 3, and Rev 5 are respectively in the +``maple-r1``, ``maple-r3``, and ``maple-r5`` subdirectories. A +schematic for a JTAG adapter suitable for use with Maple is available +in the ``jtagadapter`` directory. + +From the GitHub repository main page, you can download the entire +repository by clicking the "Download" button. If you are familiar +with `Git <http://git-scm.com/>`_, you can also clone the repository +at the command line with :: + + $ git clone git://github.com/leaflabs/maple.git + +.. _maple-failure-modes: + +Failure Modes +------------- + +The following are known failure modes. The failure modes aren't +design errors, but are easy ways to break or damage your board +permanently. + +* **High voltage on non-tolerant pins**: not all header pins are 5V + compatible; so e.g. connecting certain serial devices in the wrong + way could over-voltage the pins. The :ref:`pin-mapping master table + <maple-pin-map-master>` details which pins are :ref:`5 V tolerant + <gpio-5v-tolerant>`. + +Errata +------ + +This section documents design flaws and other errors. + +General +^^^^^^^ + +.. _maple-barrel-jack: + +* **Barrel jack power supply voltage mistake**: The acceptable voltage + range given next to the barrel jack on the Maple through Rev 5s + manufactured in Spring 2011 is **incorrect**. The given range is 7V + — 18V. In fact, **18V is too high** and should not be supplied to + your board. The original voltage regulators used on the Maple were + rated up to 18V. However, the voltage regulators on current Maple + Revs are rated up to only 16V, and due to the current draw + requirements of the board, operate properly only up to 12V. The + recommended maximum voltage you should apply is **12V**, and + potentially even lower depending upon the current draw requirements + of the application. Please see :ref:`Power Regulation on the Maple + <maple-power-regulation>` for more information. + +.. _maple-nrst-pb4: + +* **Reset and PB4 tied together**: The Maple's reset line is also + connected to PB4, which is labeled on the silkscreen as pin 43. + Thus, attempting to use pin 43 as a GPIO can reset your board. This + has other implications. Since PB4 is also the JTAG NJTRST line, + this prevents the :ref:`JTAG <jtag>` "reset halt" command from + working properly. + +.. _maple-power-supply: + +* **Power supply marketing mistake**: We originally sold the Maple + advertising that it was capable of supplying up to 800 mA; the + correct value is 500 mA. + +.. _maple-pwm-marketing: + +* **PWM marketing mistake**: We originally advertised the Maple as + having 22 PWM-capable pins; the correct number is 15. + +.. _maple-adc-marketing: + +* **ADC marketing mistake**: We originally advertised the Maple as + having 16 analog input pins. Due to :ref:`the following issue + <maple-adc-led>`, the correct number is 15. + +.. _maple-adc-led: + +* **ADC on BOARD_LED_PIN**: We originally sold the Maple RET6 Edition + advertising 16 analog input lines. However, one of them (the one on + pin 13) is also connected to the built-in LED. The voltage drop + across the LED means that the analog to digital converter on that + pin is not really useful. While it is still usable, its readings + will be incorrect. + + +By Rev +^^^^^^ + +The following subsections lists known issues and warnings for each +revision of the Maple board. + +Rev 5 +~~~~~ + +* **Pin 3 AIN missing**: Pin 3 is capable of analog input, but on Rev + 5s manufactured during Fall 2010, the corresponding "AIN" is missing + from its silkscreen. This mistake was fixed in later manufacturing + runs. + +Rev 3 +~~~~~ + +* **Pin 3 AIN missing**: Pin 3 is capable of analog input, but the + corresponding "AIN" is missing from the Rev 3 silkscreen. + +.. _maple-rev3-bad-buttons: + +* **Bad/Sticky Buttons**: a number of Rev 3 boards sold in May-June 2010 + have questionable RESET and BUT buttons. + + What seems to have happened is that the flux remover we used to + clean the boards before shipping eroded the plastic internals, which + resulted in intermittent functionality. All buttons on all shipped + boards did function in testing, but some may have been unreliable in + regular use. + + If you have this problem, we will be happy to ship you new buttons + if you think you can re-solder them yourself, or you can ship us + your board and we will swap out that part. + + For reference, the button part number is KMR211GLFS and the flux + remover we used is "Precision Electronics Cleaner" from RadioShack, + which is "Safe on most plastics" and contains: dipropylene glycol + monomethyl ether, hydrotreated heavy naphtha, dipropylene glycol + methyl ether acetate (say that three times fast!), and carbon + dioxide. + +* **Resistors on pins 0 and 1**: these header pins, which are RX/TX on + USART2 (:ref:`Serial2 <lang-serial>`), have resistors in-line + between the STM32 and the headers. These resistors increase the + impedance of the lines for ADC reads and affect the open drain GPIO + functionality of the pins. + + These resistors were accidentally copied over from older Arduino USB + designs, where they appear to protect the USB-Serial converter from + TTL voltage on the headers. + +* **Silkscreen Errors**: the silkscreen on the bottom indicated PWM + functionality on pin 25 and listen the external header GND pin as + number 38 (actually 38 is connected to the BUT button). We manually + sharpied over both of these mistakes. + +Rev 1 +~~~~~ + +* **ADC noise**: generally very high, in particular when the USB port + is being used for communications (including keep-alive pings when + connected to a computer). + + This issue was resolved in Rev 3 with a 4-layer design and a + :ref:`geometrically isolated ADC Vref plane <maple-adc-bank>`. + +* **Resistors on pins 0 and 1**: these header pins, which are RX/TX on + USART2 (:ref:`Serial2 <lang-serial>`), have resistors in-line + between the STM32 and the headers. These resistors increase the + impedance of the lines for ADC reads and affect the open drain GPIO + functionality of the pins. + + These resistors were accidentally copied over from older Arduino USB + designs, where they appear to protect the USB-Serial converter from + TTL voltage on the headers. + +* **Silkscreen Differences**: the pin numbering scheme on Rev 1 is + different from Rev 3, and thus Rev 3 software is difficult to use + with Rev 1 boards. Notably, the analog input bank is labeled A0-A4 + on Rev 1 but 15-20 on Rev 3, and the extra header bank does not have + a pinout table on the bottom. + +* **No BUT Button**: the BUT button, useful for serial bootloading, + was only added in Rev 3. As a workaround, you can directly short the + appropriate MCU pin to Vcc; see `this forum posting + <http://forums.leaflabs.com/topic.php?id=32#post-126>`_. + +Recommended Reading +------------------- + +.. _maple-stdocs: + +STMicro documentation for STM32F103RB microcontroller: + +* `Datasheet + <http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00161566.pdf>`_ + (PDF); covers STM32F103x8, STM32F103xB. +* `Reference Manual RM0008 + <http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/CD00171190.pdf>`_ + (PDF); definitive resource for peripherals on the STM32F1 line. +* `Programming Manual PM0056 + <http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/PROGRAMMING_MANUAL/CD00228163.pdf>`_ + (PDF); assembly language and register reference. +* `STM32F103RB <http://www.st.com/internet/mcu/product/164487.jsp>`_ + overview page with links to further references. + +.. rubric:: Footnotes + +.. [#frev2_4] Revs 2 and 4 were prototypes that didn't pass internal + testing. |