Have not concluded that it is the tiny20. Just checking out the data sheet based on speculation and this discussion so far.
Do you have a way to connect probes / wires to the processor?
Connect how? to have a good seat for programming it or just for probing like with a multimeter??
BTW I tried rubbing alcohol and it didn't work. The T20 is pretty much etched in I believe. I did also make a mistake in trying nail polish remover/acetone....big noob mistake ha.it got rid of the shiny part of the casing and now you cant even read the atmel or the 20sso. Chip/board still works, just now the only thing (from me) we have for studying is the pics haha. Lessons learned :)
bag06a: Connect how? to have a good seat for programming it or just for probing like with a multimeter??
Programming. But, if you're convinced it's a t20 processor, there is no point in running the experiment I had in mind.
I tried to take a picture of my board as well. I'm actually now thinking that it's a ATTINY44 versus the ATTINY20.
Update: I've added another picture so you can see where I think the numbers are.
In that top picture it does look like a "44".
• It is an SPI programmable processor (like an ATtiny44) • You can get some connections to it • RESET has not been disabled • SPI programming has not been disabled
...you can determine exactly which processor it is by reading the signature bytes. With the exception of the physical connections, making the attempt is very unlikely to damage anything. Just include series resistors; 220 ohms works well.
Good find. I do agree with you on the ATtiny44 branding. You must have had some good lights and a good magnifier or good camera (maybe with macro lens). Your text below T20Ver2 is clearer as well. Instead of 20SSO it looks more like 20SSU. From what I've seen on the Atmel site that number doesn't refer to a specific Package or anything like that, it refers to the ordering code. In the case of the ATTiny44 that ordering code links to one with the package of "SOIC (150mil) 14S1 14". Power supply for this chip is 2.7-5.5V and is 20MHz.
You probably have already seen the information, but at least I feel like i'm contributing lol.
For programming an ATTiny44 checkout this webpage as well http://hlt.media.mit.edu/?p=1695
Ok, I’m willing to give that a shot.
What do I need to connect? Do I connect the programmer’s Vcc (5v), MOSI, Reset, SCK, MISO, and Gnd to the respective pins on the ATTINY44? You mentioned 220 ohm resistors, where whould I put them? I see plenty of examples online how to program a chip in isolation, but I can’t find anything about programming a chip that’s soldered into a production board. I assumed that’s what was meant by In-System Programming, but I can’t find any good examples.
How is the target (the ATtiny84) normally powered? At what voltage?
What else is in the circuit? Is the total current less than about 350 milliamps?
The target circuit board is powered via a 9v battery, though Vcc for the ATtiny44 is +5v. The only other noteable part of the board would be the 3055L MOFET which I'm guessing is used to drive the Solenoid.
I would guess that the main draw is the solenoid, so as long as the trigger (which activates the Solenoid) is never fired, I'm pretty sure the draw is under 350mA.
Argh! Stupid brain! Pay attention!
Sorry about that. You had stated earlier that the processor runs at 5V. Apparently, my brain had gone on walkabout.
What will you be using as a programmer? An Arduino Uno?
:) No worries. I'm only pretending to know what I'm talking about. :astonished:
At the moment, I have a LcSoft USBasp programmer.
Have you used it to program an AVR processor? Are you familiar with AVRDUDE?
Do you have a link to a schematic for the programmer? It may already include series resistors. They are nothing more than a resistor connected between the programmer and the target in series. There would be three or four resistors and they are very likely the same values. 1K ohms seems to be a popular choice.
Speak of the devil..while I was typing my response, the doorbell rang to deliver my Atmel AVRISP mkII. I don't have the schematic for this one, but I think the schematic of the USBasp is here:
No for the series resistor question. I'll assume you're familiar with AVRDUDE and have used the USBASP programmer.
The first phase is to get the target to respond; no programming. I suggest powering the target using it's normal power source (the 9V battery) (but don't power the target until the end). I suggest having the programmer schematic accessiable and the ATtiny84 (44 is in the family) datasheet open to the 1. Pin Configurations section while connecting the programmer to the target. In other words, carefully review my instructions. With all the power off, connect...
• GND to GND. From the programmer schematic either pin 8 or pin 10 will work. This is connected to pin 14 (upper-right corner) on the target.
• VCC is not connected. Pin 2 on the programmer should not be connected.
• MOSI is connected to MOSI with a series resistor (220 ohms or higher). Pin 1 on the programmer is connected to a resistor which is then connected to pin 7 on the target (lower-left corner).
• MISO is connected to MISO with a series resistor (220 ohms or higher). Pin 9 on the programmer is connected to a resistor which is then connected to pin 8 on the target (lower-right corner).
• SCK is connected to SCK with a series resistor (220 ohms or higher). Pin 7 on the programmer is connected to a resistor which is then connected to pin 9 on the target (lower-right corner just above MISO).
• SS to RESET with a series resistor (220 ohms or higher). Pin 5 on the programmer is connected to a resistor which is then connected to pin 4 on the target (left side in the middle).
At this point I suggest connecting the programmer to the computer and building up an AVRDUDE command. AVRDUDE will be able to communicate with the programmer but the programmer will not yet be able to communicate with the target (no power). Include extra verbose mode (-v -v -v -v) when running AVRDUDE.
When you are content you have the command you want to run (feel free to ask on the forum for an opinion; I'm sure someone will have one) power the target and then run the command.
If all goes well AVRDUDE will read the signature bytes (it always does this) and then output the signature byte (that's the purpose of extra verbose). If that works, you are in business!
Wow thats alot of information :-. I feel extremely ill informed just by reading that and I'm realizing that I have ALOT of learning to do. I still want to partake in this project, however it will be more of a step-by-step learning experience I think.
With that said, do you have any book suggestions to read on this topic? Microconrollers/chips in general and definitely ones that cover the topics of what each pin is (such as MISO and MOSI and CLK and SCK and what not). Through a little bit of reading I know that MISO is Master In Slave Out and MOSI is Master Out Slave In (which MOSI usually connects to a MISO right?) CLK is clock I believe. I want to learn more about this stuff so suggestions would be great :)
bag06a: With that said, do you have any book suggestions to read on this topic?
Unfortunately, no. This was the last book I read on embedded programming... http://www.amazon.com/Practical-UML-Statecharts-Second-Edition/dp/0750687061 Everything I learned about AVR processors I learned from the Arduino website, Atmel datasheets, and the internet at large.
I believe the question of "which book" has been discussed a few times on the forum. I suggest spending some time with Google... https://www.google.com/search?q=book+site%3Aarduino.cc%2Fforum
Microconrollers/chips in general and definitely ones that cover the topics of what each pin is (such as MISO and MOSI and CLK and SCK and what not).
This is a fairly good description of SPI... http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus
Essentially, the programmer sends four byte programming commands, over the SPI bus, to the target, which executes those commands.
Through a little bit of reading I know that MISO is Master In Slave Out and MOSI is Master Out Slave In ... CLK is clock I believe.
(which MOSI usually connects to a MISO right?)
No. The pins are always from the perspective of the master. Master Out Slave In (MOSI) out of the master is still Master Out Slave (MOSI) in into the slave.
In the case of in-system serial programming the master is the programmer (LcSoft USBasp programmer) and the slave is the target (ATtiny84).
I want to learn more about this stuff so suggestions would be great :)
My suggestion is to get your hands dirty. Nearly anything with an AVR processor and a USB connection can act as a programmer (Uno, ATmega328 on a breadboard, LcSoft USBasp) and test targets are fairly cheap... http://search.digikey.com/us/en/products/ATTINY84-20PU/ATTINY84-20PU-ND/1245916 http://www.mouser.com/ProductDetail/Atmel/ATTINY84-20PU/?qs=2nyfZ6BV3ohscROPiyTV88GRZOsCDQSKLmyBo24c8Ug%3d http://www.newark.com/jsp/search/productdetail.jsp?SKU=68T3783&CMP=AFC-GB100000001 http://www.sparkfun.com/products/11232
Add this to the Arduino IDE... http://code.google.com/p/arduino-tiny/
And you are ready to go!
Every now and then I really wish I wouldnt have left school for Computer Science after 2 years haha. But I guess it is what it is ya know?
I ordered a few ATTiny44 chips since I don't want to test on the phenom board just yet. Once those chips arrive, I'll try the steps you recommend. I tried the steps on the ATTiny20 chips (with different pin positions based on the datasheet), however, no matter what I tried I could not get the AVRISPmkII Programmer to read or write to the chip.
Well....I tried programming a brand new ATtiny44 with several different programmers including the Atmel AVRISP mkII using AVR Studio 6, USBasp using avrdude, and an arduino Uno with Arduino IDE. I tried first with the Atmel mkII since it was Atmel branded and the chips were Atmel, I figured I would go the Atmel route all the way. No matter what I tried, I could not get the programmer to read or write program data. I was able to get it to read the target voltage, and the LED on the mkII went from red to green when I connected the pins according to their documentation, but nothing.
Next, I tried the USBasp with avrdude. With this, I kept getting the error "avrdude: warning: cannot set sck period. please check for usbasp firmware update." I didn't get far with this solution. I could do more research to try and figure out what's wrong, but instead I moved on to the Arduino as an ISP.
The Arduino Uno as an ISP did something. I can't say what exactly, but once I configured the Arduino to be an ISP (uploaded the ArduinoISP sketch and changed some settings in the IDE), I was able to deploy to my test ATTiny44. To test my deployment, however, I hooked up an LED to one of the pins and got nothing (I deployed the blink sketch). I changed the blink program to turn multiple pins on and off just in case I got the wrong one on the board. Still nothing. At this point, I gave up and decided to try the Atmel mkII approach again, thinking that since Arduino worked a little, maybe I'd have better luck this time.
I don't know what the Arduino did, but when I got back into the AVR Studio 6 IDE, I could read and write to the chip. At least that's what the tool said it was doing. I was able to read Lock, Memory, and Fuse information. I was even able to "deploy" a simple application (similar to Blink) to the chip....at least the deployment didn't fail. The program was still not working (no LEDs were being lit). It's like the program is not making it to the chip.
I checked the LED, and it is working, and I made sure I had the polarity proper when putting it in the circuit.
I'm not sure what I may be doing wrong, I'll try some more combinations tomorrow.
Any ideas why the Atmel route would not recognize the chip until Arduino wrote something to it? How do I initialize virgin chips?