Administering the protocol within USBASP is easier than you think

Top-notch handheld programmers are certainly hard to come by, unless you choose to shop with us of course. We have everything from AVR models to PIC and SAMD designs, each of which are suitable for both production and field applications. Coming with a considerable assortment of features, and having separate adapters and connectors available for purchase if required, ours are the devices you can trust.

XMEGA is one of the more recent additions to the AVR group of microcontrollers, having only been in use for a few years. Aside from looking amazing, they possess a greater level of speed with 32MHz, a modular design, a higher number of peripherals, and best of all, you can use the utensils you’re already familiar with in conjunction with the programmer. The only downside is that they don’t make use of the most common ISP programming header one finds on almost every AVR dev board.

The good news however is that administering the programming protocol in USBASP isn’t overly challenging. Many thought it impossible at first because the PDI needs a continuously clocking signal. Furthermore, if the clock rate falls under 10 kHz, the PDI ends up disconnecting. Stern timing is an issue for the V-USB aspect of the controller too. This is what directs every USB transmission within the software, but it can’t perform both in unison.

Tests conducted with the apparatus revealed that the interrupt managing a simple control transfer managed to steal 40 to 50 us only. This was short enough that the dependable PDI bit banging was allowed to happen. Sending further payloads would lead to the clocking breaking. However, users can arrange for it to operate in batches so that it’s capable of only starting the PDI transmissions after acquiring all the USB data.

At Kanda, we provide our XMEGA handheld programmers both as part of a starter kit and as detached entities. Our products function alongside the other USB dongles we supply and are sure to leave you with far fewer headaches than you would have had using different machinery.

If there’s anything we can assist you with, please give us a call. We can go over the specifications of the devices and help clients to choose the right device.

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