diff options
Diffstat (limited to 'docs/source/hardware')
| -rw-r--r-- | docs/source/hardware/maple.rst | 200 |
1 files changed, 183 insertions, 17 deletions
diff --git a/docs/source/hardware/maple.rst b/docs/source/hardware/maple.rst index 874ee82..44a5238 100644 --- a/docs/source/hardware/maple.rst +++ b/docs/source/hardware/maple.rst @@ -8,6 +8,30 @@ Maple .. contents:: Contents :local: +Technical Specifications +------------------------ + + * MCU: **STM32F103RBT6**, a 32-bit ARM Cortex M3 microprocessor + * Clock Speed: **72 MHz** + * Operating Voltage: 3.3V + * Input Voltage (recommended): 3V-12V + * 39 Digital I/O Pins (:ref:`GPIO <gpio>`) + * 16 Analog Input Pins + * 12-bit **ADC** resolution (:ref:`ADC <adc>`) + * 15 **PWM** pins at 16-bit resolution (:ref:`PWM <pwm>`) + * Dedicated **USB** port for programming and communications (:ref:`USB<usb>`) + * External **JTAG** interface (:ref:`USB <jtag>`) + * **128 Flash** and **20KB SRAM** + * 64 Channel nested vector interrupt handler (including external interrupt on GPIOs) + * Integrated **SPI** (:ref:`SPI<spi>`) + * Integrated **I2C** (:ref:`I2C<i2c>`) + * 7 Channels of Direct Memory Access (**DMA**) + * 3 **USART** divices (:ref:`USART <usart>`) + * Four 4-channel **timers** (:ref:`Timers <timers>`) + * Supplies up to 800mA @ 3.3v + * Support for low power and sleep modes (<500uA) + * Dimensions are 2.05″x2.1″ + .. _maple-hardware-identify-rev: Identifying your Rev @@ -16,17 +40,22 @@ 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. Known issues are listed in the :ref:`errata <errata>`. +Rev. Known issues are listed in the :ref:`errata <maple-errata>`. -Rev 1 +Rev 5 ^^^^^ -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. +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_rev1.png +.. figure:: /_static/img/maple_rev5.png :align: center - :alt: Maple Rev 1 + :alt: Maple Rev 5 Rev 3 ^^^^^ @@ -40,20 +69,15 @@ It also includes a built-in LiPo battery charger. :align: center :alt: Maple Rev 3 -Rev 5 +Rev 1 ^^^^^ -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. +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_rev5.png +.. figure:: /_static/img/maple_rev1.png :align: center - :alt: Maple Rev 5 + :alt: Maple Rev 1 .. _hardware-maple-powering: @@ -99,8 +123,150 @@ at the command line with :: $ git clone git://github.com/leaflabs/maple.git +.. _maple-errata: + +Errata +------ + +This section lists known issues and warnings for each revision of the +Maple board. The failure modes aren't design errors, but are easy ways +to break or damage your board permanently. For a list of differences +between the Maple and Arduinos, see the :ref:`Arduino Compatibility +reference <arduino-compatibility>`. + +The errata are grouped by Maple version ("Rev"). + +Maple Rev 5 +^^^^^^^^^^^ + +Known issues: + +* **Pin 3 AIN missing**: Pin 3 is capable of analog input, but the + corresponding "AIN" is missing from its silkscreen. + +* **GPIO 39-43 not configured**: this is really more of a software + "TODO" item. Some of the JTAG header pins are numbered 39-43. These + STM32 pins are indeed fully functional :ref:`GPIO <gpio>` when a + :ref:`JTAG <jtag>` device is not connected, but we have not enabled + them in software and thus they can not be accessed with the regular + :ref:`lang-pinmode` or :ref:`lang-digitalwrite` functions. + +Potential failure modes: + +* **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 Mega Table + <pin-mapping-mega-table>` details which pins are 5V-tolerant. + +Maple Rev 3 +^^^^^^^^^^^ + +Known issues: + +* **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 (really?), 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. + +* **GPIO 39-43 not configured**: this is really more of a software + "TODO" item. Some of the JTAG header pins are numbered 39-43. These + STM32 pins are indeed fully functional :ref:`GPIO <gpio>` when the a + :ref:`JTAG <jtag>` device is not connected, but we have not enabled + them in software and thus they can not be accessed with the regular + :ref:`lang-pinmode` or :ref:`lang-digitalwrite` functions. + +* **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. + +* **PWM Marketing Mistake**: We originally sold the Maple advertising + 22 channels of 16-bit hardware PWM; actually the Maple only has 15. + +Potential failure modes: + +* **TTL voltage on non-tolerant pins**: not all header pins are 5V + compatible; connecting certain serial devices in the wrong way could + over voltage the pins. The :ref:`Pin-Mapping Mega Table + <pin-mapping-mega-table>` details which pins are 5V-tolerant. + +Maple Rev 1 +^^^^^^^^^^^ + +Known issues: + +* **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 + geometrically isolated ADC V\ :sub:`ref` plane. + +* **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>`_. + +* **PWM Marketing Mistake**: We originally sold the Maple advertising + 22 channels of 16-bit hardware PWM; actually the Maple only has 15. + +Potential failure modes: + +* **TTL voltage on non-tolerant pins**: not all header pins are 5v + compatible; connecting certain serial devices in the wrong way could + over voltage the pins. The :ref:`Pin-Mapping Mega Table + <pin-mapping-mega-table>` details which pins are 5V-tolerant. + +Recommended Reading +------------------- + +* STMicro documentation for STM32F103RB microcontroller: + + * `Datasheet <http://www.st.com/stonline/products/literature/ds/13587.pdf>`_ (pdf) + * `Reference Manual <http://www.st.com/stonline/products/literature/rm/13902.pdf>`_ (pdf) + * `Programming Manual <http://www.st.com/stonline/products/literature/pm/15491.pdf>`_ (assembly language and register reference) + .. rubric:: Footnotes .. [#frev2_4] Revs 2 and 4 were prototypes that didn't pass internal testing. - |