Quote:
Originally Posted by ciprians
Hi, the +24V will be used only if you populate the DC-DC converter on PCB. The converter is not really required, and you can use the power connector to provide the required programming voltage.
On EPROM, pin 14 for GND & pin 28 for +5V, where the +5V is provided by arduino nano.
For reading, only the USB connection to arduino will be used, but to write you will also need to provide the programming voltage using the power connector.
Also the PCB, which now is double sided, can be easily converted to single sided with THT components.
If you think, it will be useful to you, I can provide with my single sided PCB drawing (it's a little bit messy as there are a lot of connection wires, but it's working)
|
Thanks for the clarifications - I guess if '+24V ' had been called +Vpp to reflect it's potential multiple voltages (or +12V5 for just the 'C' devices), that
might have not confused me so much as to what was being done.
And having a DC-DC converter available with the required Vpp voltages / adjustable to fine-trim to exact voltage / maybe switching between common ones could be useful, otherwise it's probably simplifies not having it.
Thanks for offer of S/S PCB layout, but I'd probably be tempted to just build something like this on veroboard / VQ-matrix board or a shield prototyping board I've got. I don't myself have an immediate need, as I have a few commercial programmers, although they only handle 27xx ones, so have to use adaptors I've made. Although I might put one together sometime, to have a play with it for interest.
I've been considering trying to make something for the Arduino (2560) Mega, that could handle even more pins to be able test many digital peripheral IC's etc. as have seen some RAM IC testers etc. shields for these.