Looking for something else I ran across the above article (on CPCRulez) from a 1988 issue of Practical Electronics:
https://cpcrulez.fr/hardware_montage_8x-temperature-analogue_interface.htm
Of minimal interest to myself but I thought might be something for the hardware fans to chew over.
Pretty nice design, but the address decoding is a pain.
Maybe somebody wants to overwork it for 2022?
Interesting. I built an almost identical circuit way back when, but to measure voltage instead of temperature. It was my CPC Multimeter (with datalogging :) ).
Bryce.
Datalogging - using a BASIC program?
Yup.
Bryce.
Quote from: Bryce on 10:00, 30 November 22Interesting. I built an almost identical circuit way back when, but to measure voltage instead of temperature. It was my CPC Multimeter (with datalogging :) ).
Bryce.
Why don't you do a new version of it? Just to measure the Volts of the CPC itself. :o So, eventually we can tell how much Volts our CPC gets. And then all nicely packed on a M4 card. Should be easy for you since you already made your schematics. Sadly the F1-D clone was to complex I guess. I'm sure you would do the CPC scene a great favour. :)
I'll have to go searching. The schematics were most likely hand drawn, I didn't have fancy software back then. I'd also have to make some changes though if it's to measure the voltage that it's being fed by. That's a bit more complicated.
Bryce.
Hand drawn schematics! Put them on ebay and you won't need to work next year. :laugh:
Quote from: GUNHED on 03:21, 04 December 22Hand drawn schematics! Put them on ebay and you won't need to work next year. :laugh:
I doubt that. They aren't a hand drawn original of the Altair 8800 schematics, just an AD converter for a CPC. :)
Bryce.
i was thinking how cool it would be to program a robot arm or even an entire robot on the CPC - Johnny 5 style. Even the hand likely needs a dozen I/Os, I wonder if you know any controllers that could connect to a CPC via serial port perhaps that give a useful number of I/Os for robot control? or perhaps house and lighting control? I'm thinking a cool Inseminoid computer that is Amstrad CPC based.
I have an Ambug Robot (in pieces) somewhere https://www.cpcwiki.eu/index.php/Ambug . It uses basic i/o to control two motors, but in theory you could connect hundreds of relays to a whole set of addresses and control whatever you wanted at whatever voltage the relays are designed for.
Bryce.
Or you could try Lego Mindstorms sensors and motors. They all have I2C serial interfaces which the CPC is easily capable of bit banging out. There are many open source projects based around Arduino or ESP32 micros for this.
Yes, except that they are an incredibly expensive way of getting sensors or motors for a project. The sensors and motors are standard parts with a massive price increase for some plastic and a Lego logo.
Bryce.
Quote from: revaldinho on 23:32, 05 December 22Or you could try Lego Mindstorms sensors and motors. They all have I2C serial interfaces which the CPC is easily capable of bit banging out. There are many open source projects based around Arduino or ESP32 micros for this.
ive been looking into bitbanging i2c to drive some IOs via printer port...to either connect an arduino/esp32 or directly connect i2c based sensors.. (which i have a bunch of for arduino/esp stuff)
but not sure how to set it up to get the data in when theres only one input pin on the printer port..
..and how well will the cpc respond to sensor data...
bitbanging i2c on printer port is fine for output only (eg LCD display)..but input is the pain...
im thinking it would be easier to connect an arduino mega2560 on the expansion port and then using that to pull in the sensor data and send it to the cpc..aswell as other things (like usifac features)
Quote from: WacKEDmaN on 11:00, 06 December 22but not sure how to set it up to get the data in when theres only one input pin on the printer port..
For this you'll need to use an accurate timing and something like Manchester codification.
https://en.wikipedia.org/wiki/Manchester_code
Quote from: WacKEDmaN on 11:00, 06 December 22im thinking it would be easier to connect an arduino mega2560 on the expansion port and then using that to pull in the sensor data and send it to the cpc..aswell as other things (like usifac features)
If you already have a serial port on the CPC side like an Usifac, simply use it to communicate with the arduino.
The only thing you need to convert separate output and input pins into a real open-drain io is a logic-level fet transistor. Output pin goes to the gate, source goes to ground, and drain is connected to both SDA and the input pin. You would also need a pullup resistor on SDA if you haven't one already, as the output can only pull the bus low.
If you pick /STROBE as the output pin, the output pin will even behave as you expect instead of inverted.
Quote from: ajcasado on 11:41, 06 December 22Quote from: WacKEDmaN on 11:00, 06 December 22but not sure how to set it up to get the data in when theres only one input pin on the printer port..
For this you'll need to use an accurate timing and something like Manchester codification.
https://en.wikipedia.org/wiki/Manchester_code
Quote from: WacKEDmaN on 11:00, 06 December 22im thinking it would be easier to connect an arduino mega2560 on the expansion port and then using that to pull in the sensor data and send it to the cpc..aswell as other things (like usifac features)
If you already have a serial port on the CPC side like an Usifac, simply use it to communicate with the arduino.
well that was the plan...but usifac doesnt want to work on my system...
and yeah manchester encoding would be the way to go.. just like loading a tape in..
Joystick port could be used for input...
I believe the Ambug robot used the printer port for motor control, and joystick port for sensors?
Quote from: Animalgril987 on 00:31, 07 December 22Joystick port could be used for input...
I believe the Ambug robot used the printer port for motor control, and joystick port for sensors?
i was thinking about using the Busy pin...
should also be able to use it as an input...and run the SDA line from it in both directions.. (SCL on strobe)
schematic says Busy pin is an out..but ive seen it used as an in..
Busy goes straight to the PPI, so it can be either input or output. It's definitely intended as input on the cpc, because it is a signal from the printer.
All the other pins on the printer port are latched and can only be outputs.
Don't put SCL on strobe - you don't want that inverted, and you actually *do* want SDA inverted (the transistor inverts it again, resulting in the correct sense.)