Status Boards: Difference between revisions

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The driving of the 16 LEDs poses an interesting problem due to the limited number of digital outputs on the NodeMCU: we are looking for a simple low-cost solution so after looking at various ICs to perform the task I decided to throw in another inexpensive micro with plenty of I/O and control it with I2C, serial or similar.
The driving of the 16 LEDs poses an interesting problem due to the limited number of digital outputs on the NodeMCU: we are looking for a simple low-cost solution so after looking at various ICs to perform the task I decided to throw in another inexpensive micro with plenty of I/O and control it with I2C, serial or similar.
== Using a cheap ProMicro for I/O ==
The NodeMCU can tell the ProMicro what outputs to drive with a simple serial protocol: -
* ASCII for human convenience and same parsing code on both micros
* same interface on both UARTS - USB and HW for simplicity and testing
* The ESP8266-E is not 5v tolerant on the UART so I shall use a voltage divider
** https://cdn-shop.adafruit.com/product-files/2471/0A-ESP8266__Datasheet__EN_v4.3.pdf

Revision as of 13:05, 28 March 2016

Simple means of showing status of Hackspace stuff on web and physical boards.

The driving of the 16 LEDs poses an interesting problem due to the limited number of digital outputs on the NodeMCU: we are looking for a simple low-cost solution so after looking at various ICs to perform the task I decided to throw in another inexpensive micro with plenty of I/O and control it with I2C, serial or similar.

Using a cheap ProMicro for I/O

The NodeMCU can tell the ProMicro what outputs to drive with a simple serial protocol: -