#CHALLENGE 37 PULL THE PIN SERIAL#
#CHALLENGE 37 PULL THE PIN PLUS#

Next, find pins that are bus capable, aka вЂfast writeвЂ™ capable.

Next, find pins that are purely GPIO capable pins (no ADC or PWM).

Next, find pins that are purely PWM capable pins.

Once dedicated hardware is roughed out and connected, find pure analog capable pins.Should we dedicate some unused IO to a 2nd SPI port? 2nd UART? 2nd I2C? Are there other peripherals that can be exposed on the SAMD51 to the card edge? For example, SAMDs have flexible SERCOM ports.Now itвЂ™s time to make some architecture decisions: Does this processor support a Clock Out or special clock generation pin (output)? If so, connect to the AUD_OUT/CAM_MCLK pin.Route any power from RTC_3V on the edge connector to any pins on the processor that need power from a coin cell or mini battery to run the RTC.Only processors that can sleep and wakeup from RTC / low power battery backup should be able to turn off the main CB voltage regulator. This allows the PB to turn off the main voltage regulator on the CB. This pin will read the VIN voltage through a в…“ voltage divider located on the CB. Dedicate one ADC capable pin to BATT_VIN/3.Are there any pins on this processor capable of I2S, PDM, CAN, or USB host? * Be sure to connect those and give them priority over the general ADC, PWM, GPIO connections.Does this processor have differential ADC capabilities? If so, connect the differential ADC pins to ADC+/- (G9/10).Does this processor support SWD? Connect SWDIO and SWCK as needed.Invert this signal and/or add circuitry as needed to work with this processor if needed. The carrier board can have a вЂbootвЂ™ button that pulls this pin low. Does this processor need special boot pin controls? The Boot pin is input open drain.So be sure to keep the pull up on reset on the PB. The reset pin on MM is defined as an output open drain.RX LED, TX LED connections get removed entirely.Flash pins go to onboard flash (no move).Primary I2C pins on SAMD51 connect to primary I2C pins on MM.

Connect USB +/- on processor to USB +/- on MM edge connector.

In the schematic, begin connecting the various dedicated hardware pins on the microcontroller to the MM card edge. Combine duplicate GND pins, VDDIO pins, etc into single pins on the schematic component. Now is your chance to clean up the schematic component for the processor. For a hypothetical example, users may be populating the SAMD51 boards with a 32mbit flash as opposed to the older 16mbit flash. This enables the user to immediately test their processor board agnostic of the capabilities of the carrier board.Д¬heck to see if there have been any changes or improvements to the general design using this processor. The exception to this is every Processor Board shall include one status LED connected to a pin that is not connected to the board edge. This includes TX/RX LEDs, Power LEDs, charge LEDs, etc.

Remove all LED indicators that will be relocated to the carrier board. Retain any boot control circuitry (Artemis and ESP32 have boot pins that need to be controlled by RTS/DTR).

#CHALLENGE 37 PULL THE PIN SERIAL#

This means you may need to include a USB to serial IC ( CH340E is recommended) for devices that donвЂ™t have built-in USB peripherals. Keep anything needed for the device to be programmed by only USB +/. USB to serial conversion IC and circuitry.1 status LED (usually connected to LED_BUILTIN).External memory to enable Python script loading.Keep any needed external circuitry such as:

#CHALLENGE 37 PULL THE PIN PLUS#

Start with a known good development board product, the SAMD51 Thing Plus for example, and remove all the bits from the EAGLE design that are not needed from the schematic: In this case, we'll start with a development board and convert it to a MicroMod Processor Board (PB). Instead of starting from scratch, we'll start with a known good development board.

Challenge 37 pull the pin