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Re: Adventures with I2C & Minerva Mk2
Posted: Wed Sep 10, 2025 3:57 pm
by t0nyt
Going back to the AT24C256 (32KB) device
The new one arrived today and it does exactly the same as 4 of the original 5
If they ALL did the same it would be better I think but having 1 that works is a bit confusing!
All have the ghost address (address+8), but there's nothing I can really do about that!
Am going to play with my test code to try and work out if it's the write or the read that's failing. Or just my code is duff (have got a much better understanding of how i2c_io works now)
Maybe I also need to look for an alternative device that does the same thing
Re: Adventures with I2C & Minerva Mk2
Posted: Wed Sep 10, 2025 4:52 pm
by t0nyt
t0nyt wrote: Wed Sep 10, 2025 3:57 pm
Going back to the AT24C256 (32KB) device
The new one arrived today and it does exactly the same as 4 of the original 5
If they ALL did the same it would be better I think but having 1 that works is a bit confusing!
All have the ghost address (address+8), but there's nothing I can really do about that!
Am going to play with my test code to try and work out if it's the write or the read that's failing. Or just my code is duff (have got a much better understanding of how i2c_io works now)
Maybe I also need to look for an alternative device that does the same thing
Ok, it was my code...
Took one look at the "page" write code and, with my better understanding of i2c_io now, instantly saw the mistake. Have corrected the code in the original post (line 150 needed LEN(v$) to LEN(V$)+2. No idea why one of them worked, I guess that's the faulty one!
No idea what's going on with the "ghost" address though and nothing I can do about it as far as I know
Re: Adventures with I2C & Minerva Mk2
Posted: Wed Sep 10, 2025 6:40 pm
by t0nyt
I've tried connecting the Speech Synthesiser to my screen (basically a TV with VGA input and a 3.5mm jack for audio input - works fine with QSound output)
But all I get is a very short crackle and then the speech module dies until power cycled
I'm assuming there is some kind of electrical imbalance going on that I don't understand, given my poor electronics knowledge
Does anyone have any thoughts please?
Many thanks
Tony
Re: Adventures with I2C & Minerva Mk2
Posted: Wed Sep 10, 2025 6:43 pm
by XorA
t0nyt wrote:I've tried connecting the Speech Synthesiser to my screen (basically a TV with VGA input and a 3.5mm jack for audio input - works fine with QSound output)
But all I get is a very short crackle and then the speech module dies until power cycled
I'm assuming there is some kind of electrical imbalance going on that I don't understand, given my poor electronics knowledge
Does anyone have any thoughts please?
Many thanks
Tony
You have the 0v line connected all the way through?
Re: Adventures with I2C & Minerva Mk2
Posted: Wed Sep 10, 2025 6:49 pm
by t0nyt
XorA wrote: Wed Sep 10, 2025 6:43 pm
You have the 0v line connected all the way through?
There's 2 output terminals labelled Positive & Negative and they all go thru to the same +/- connections at the TV end
I'm assuming 0v = negative?
Thanks
Tony