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SiriusHardware · 29th Nov 2022, 8:18 pm

One consideration when basing it on any common microcontroller board is how much current the programmer hardware will need during programming pulses - potentially quite a lot, and if the supply to the Arduino (or whatever) is limited to the standard USB 500mA then it could be necessary to organise an independent more current capable 5V supply for the programmer hardware. In Chris's original Acorn based version this won't have been a significant problem because the +5V supply was presumably drawn from a more than adequate +5V supply on the rack it was meant to be plugged into.

Raspberry Pi Zero and Pi 4 apparently pass their +5V supply unfused to the +5V output pin on the GPIO port and both devices presumably negotiate for more than 500mA from whatever micro USB supply they are powered from.

29th Nov 2022, 8:18 pm	#32
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: Tesla Programmer One consideration when basing it on any common microcontroller board is how much current the programmer hardware will need during programming pulses - potentially quite a lot, and if the supply to the Arduino (or whatever) is limited to the standard USB 500mA then it could be necessary to organise an independent more current capable 5V supply for the programmer hardware. In Chris's original Acorn based version this won't have been a significant problem because the +5V supply was presumably drawn from a more than adequate +5V supply on the rack it was meant to be plugged into. Raspberry Pi Zero and Pi 4 apparently pass their +5V supply unfused to the +5V output pin on the GPIO port and both devices presumably negotiate for more than 500mA from whatever micro USB supply they are powered from.