BasicMicro - Forums

Hello everyone, I have just got my Nano 28x and this usb to ttl converter: http://cgi.ebay.com.au/USB-2-0-UART-TTL-6PIN-Module-Serial-Converter-CP2102-/180650378506?pt=LH_DefaultDomain_2&hash=item2a0f9a050a i managed to program it once with the blinking led but it wont program again its quite annoying, any suggestions on what to do, i have it wired up on a breadboard like the 2nd schematic on the datasheet
edit: i can program it its just an odd process to go through to doit

Please post the process. We may be able to simplify it or at least others with a similar issue may be helped later. Thanks.

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Tech Support
Basic Micro - Robotic Technology Evolved

True i should have posted it sorry ,
All i have to do is go to the prefrences and click find processor and quickly turn on the power to the nano 28x (i have a switch on the for the power because im using it from the power from the usb stated in my first post) and it should say processor found and then i can program it or whatever i want to do, i think this method just prevents the processor from running the program in the flash memory so it can program or whatever. but yeah if that didnt make sense tell me and ill fix up some parts

Hmm, What you are doing is causing the bootloader to run(runs after a reset) which gives you about 100 to 200ms to get into boot mode. It sounds to me like the Nano can't be reset by your USB to Serial adapter. This could be because of how you have it wired or because the USB to Serial adapter you are using doesn't bring out the RTS or DTR signals. One of those signals should be connected to the reset pin of the Nano(through an appropriate level converter/inverter for those not using a TTL adapter).

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Tech Support
Basic Micro - Robotic Technology Evolved

Well i have the RST(usb adapter) pin directly connected to the reset pin of the nano, the RST pin gives an output. i also tried putting 10k resistor instead of the wire if you know what i mean, it didnt change at all. i think it could possibly be that i am using the 5v power source from the USB adapter i havent checked what its exact voltage is yet. would an external power source change it at all?
Its wired like my attachment, anything written in black goes to the usb (except for the pins obviously) and sorry for my laziness.

Yep, you burned yourself the same way I did.

I also took it for granted that the adapter's RST pin was an output. Actually, it is an INPUT to the adapter, and is used to restart the adapter itself! Mine was another store's product, but I believe it too used the CP chip, so you probabaly have the same problem. I traced the RST pin back to the pin on the chip itself, then looked up its function on the appropriate data sheet.
Oh, well, at least these things are cheap!
Take care.

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kenjj
http://blog.basicmicro.com/
http://kjennejohn.wordpress.com/

well thats odd, how crap. ah well looks like im just gonna have to be a retard and flick the switch a whole lota times to get in the right time. how can i reset the nano with a momentary switch or cant i?

Let's see, you get a timeout something like 200 milliseconds after you release the reset switch where the Atom looks for communications with a PC wanting to program in the code you just wrote. So, get the cursor over the "Program" button, press/release the reset switch, and press the mouse button to start the programming process.

The reset switch can be any simple momentary Normally Open (NO or N/O) switch (or a piece of wire, for that matter!). Install a pullup resistor (Oh, 10K to 47K) to the Atom's reset pin. Then wire the switch to the reset pin on one side, the other side goes to ground.

Now, when you apply power, the resistor will supply a weak high to the reset pin, which keeps it out of reset. When you press the switch, this puts a low on the reset pin, which forces a reset. When you release the switch, and the pin goes high, the autoloader programmed into the Atom at the factory kicks in. It takes 200 or more mS to detect an attempt from the PC through the serial/USB port to signal a waiting download. As long as you hit the "program" button on the screen soon enough, you should be downloading toot sweet.

Try it and let us know how it goes!

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kenjj
http://blog.basicmicro.com/
http://kjennejohn.wordpress.com/

Thanks a lot Kenjj, i'll give it a go tomorrow when i get to school and i'll tell you how it goes