We sent out a new design for a test run about a week ago.
The major changes are: UART is now on every port. A lot of commonly used chips use UART for communication. Every port now supports UART, SPI, and I2C communication protocols. We have hardware UART on three module ports and software UART on the fourth module port and the gpio port. We have two different I2C ports. Port banks A, B, and the GPIO bank use one I2C port, while banks C and D use another. Because I2C uses the same two lines to talk to all the ports, this can create a problem if you want to hook up two of the same I2C devices to Tessel. For example, two Accelerometer modules would clash with each other trying to talk at the same time. Now one Accelerometer module can be hooked up to bank A and another can be hooked up to bank C without clashing. USB power and external power now switches smoothly. In our last revision we had an issue where Tessel would brown out during power switches.
We’ll be getting back the new Tessels late this week/early next week from our manufacturer.
We’ve split up Ambient into two different modules, one for sound/visible light, and another for infrared (IR) sending/receiving. Everyone who ordered an Ambient module before now will get both the Ambient and the IR modules.
We felt that combining these into one module stuck too many features together, and most people we talked to either wanted ambient sensing or IR transmissions. Our goal for Tessel is to make hardware abstractions that make sense, and combining low precision data (such as ambient) with data that needed signal processing (such as IR) felt that we were trying to do too many things at once.
Splitting the modules up frees up space on the ambient module, which we’re using to compute the “loudness” in hardware, as opposed to doing so in software. This means that the ambient sensor will let you quickly determine the ambient noise level or run your own algorithm on the incoming analog signal.
We’ve made the switch from the BLE112a to the BLE113a module. The BLE113a is not only smaller in size, but it also has a lower power draw, so you have a little more wiggle room with your other modules.
We sent out the Accelerometer about a month ago to a manufacturer for the production run. They’re done making them and are now testing them. We should get them back in the next week or so. If these turn out well, we’ll begin to do production runs of the other modules we’ve finished.
As always, you can see our progress here http://tessel.io/status
–Jon, Kelsey, Tim, Jia, and Eric