I see, you are using the arduino as the programmer for a new chip.. If the arduino is at 16MHz and SPI is /128 it could be too high (125KHz), sure. It would be better to go down to ~1kHz for the new chip fuses reflash.
For example the usbasp programmer ($3.80 at ebay incl shipping costs) had a switch for "slow clock" setting specifically for programming chips set to a low fcpu (ie 1MHz). The newest driver has got the -Bxyz option for that, so I must not tackle the switch anymore..
Well, I think I have a bit-banging SPI implementation now, but it still doesn't work - exactly the same results, just slower.
This is my bitbanging code - if you someone could just make sure that it is doing what I hope it is - it should be the equivalent to SPI mode CHPA=0 and CPOL=0:
This is my bit-banged SPI code which works successfully programming various chips:
// bit banged SPI pins
const byte MSPIM_SCK = 4; // port D bit 4
const byte MSPIM_SS = 5; // port D bit 5
const byte BB_MISO = 6; // port D bit 6
const byte BB_MOSI = 7; // port D bit 7
// for fast port access (Atmega328)
#define BB_MISO_PORT PIND
#define BB_MOSI_PORT PORTD
#define BB_SCK_PORT PORTD
const byte BB_SCK_BIT = 4;
const byte BB_MISO_BIT = 6;
const byte BB_MOSI_BIT = 7;
// control speed of programming
const byte BB_DELAY_MICROSECONDS = 4;
...
// Bit Banged SPI transfer
byte BB_SPITransfer (byte c)
{
byte bit;
for (bit = 0; bit < 8; bit++)
{
// write MOSI on falling edge of previous clock
if (c & 0x80)
BB_MOSI_PORT |= _BV (BB_MOSI_BIT);
else
BB_MOSI_PORT &= ~_BV (BB_MOSI_BIT);
c <<= 1;
// read MISO
c |= (BB_MISO_PORT & _BV (BB_MISO_BIT)) != 0;
// clock high
BB_SCK_PORT |= _BV (BB_SCK_BIT);
// delay between rise and fall of clock
delayMicroseconds (BB_DELAY_MICROSECONDS);
// clock low
BB_SCK_PORT &= ~_BV (BB_SCK_BIT);
}
return c;
} // end of BB_SPITransfer
I see the SCK line clocking. I see the MOSI line sending data. There is nothing on the MISO line. It's like the chip is just sat on a park bench somewhere whistling a happy tune all by itself ignoring everything that's going on around it. In a world of its own.
If I rip all the pins off then I have one of those, yes
I haven't touched retro for a while - kind of got behind with it. The multi-uart code I was working on didn't work too well - something strange with interrupts. The last time I tried running Retro on my setup it wouldn't boot I need to get back on it sometime - at the moment my Eurocard Computer is running the Max32 bootloader so it's kind of like a glorified Arduino
.."I haven't touched retro for a while.." There is a lot of news (ie spi, ethernet..) so maybe you might try to boot it again and join us - a lot of challenges there
pito:
I see, you are using the arduino as the programmer for a new chip.. If the arduino is at 16MHz and SPI is /128 it could be too high (125KHz), sure. It would be better to go down to ~1kHz for the new chip fuses reflash.
Factory-fresh chips should be running at 1MHz, so as long as the SPI clock is below 250kHz it ought to be ok.
You could always try using the clock pre-scaler, which can reduce the system clock by up to 256x. eg:
There's always the possibility the new chips are genuinely dead for some reason. A way of ruling out programming problems, albeit high-risk, would be to set the fuses of the working ATmega328p to their factory defaults and then try reprogramming it. Something like this:
(making sure to reset the clock-related fuses last)
majenko:
pito:
Do you have:
Xtal connected to the brand new 328p?
Yes.
If the chip is using its internal clock, as it should be if it's brand new, there's no need to connect an external crystal. OTOH, having a crystal there shouldn't disturb SPI communications. Majenko, could you post a photo of your setup?
A way of ruling out programming problems, albeit high-risk, would be to set the fuses of the working ATmega328p to their factory defaults and then try reprogramming it.
No thanks
I don't want to brick a good chip.
You could always try using the clock pre-scaler
I'll give that a go.
could you post a photo of your setup?
Sure, here it is. Decoupling caps and crystal load caps are all SMD on the reverse side.
I'm not familiar with that PCB - I assume it does all the power routing. The brown reset wire doesn't seem connected - is it connected on the underside of the PCB? Anyway you already said that it works with a chip pulled out of an Uno, so it must be ok.
The only thing I can think of left to try is Nick Gammon's board-detector sketch That would rule out any strange avrdude problems. He also suggests some breadboard layouts for different clock configurations, in case your chips are configured to use an external clock for some strange reason.
majenko:
The board detector program detects a known good chip fine. With one of the new chips, it doesn't detect it at all.
If my board detector is set up to detect a known good chip, and then you insert a "factory fresh" one and nothing happens, sounds like it might be dead. After all, I tested it on factory chips.
You could slow down the SPI in the board detector, but I haven't needed to do that yet.
Right. The guys at Farnell have kindly sent me a couple of new '328P chips. I'm about to see if they work.
I'll type as I do it so you can see exactly what I am doing. I haven't even opened the envelope with the chips in.
Right, first things first, on goes my trusty wrist strap. I'll put down the cat (put it on the floor that is, not take it to the vets), and stop rubbing my hair with this baloon, and grab me an Arduino.
Right, that's the Board Detector loaded, and the programming shield plugged in. Now to open the envelope...
The antistatic packaging is good - a bag and a tube...
Slide one chip out of the tube on to my wooden desk, grasp it by both ends (not the legs) and slot this bad boy in.
Plug in Ardy, open the serial monitor...
Atmega chip detector.
Just to test, grab second Ardy, pop the chip, slip that in to the programming shield, and voila - it works.