Have a Raspberry Pi? Want to build a robot? Need to drive some engines? or thousands of LEDs? Then you will love the gertbot!
The gertbot is a HAT-board for the Raspberry Pi that adds four H-bridges, two open-drain N-MOSFETs that can handle some serious power. It is also possible to cascade up to four boards, giving you 16 H-bridges and 8 MOSFETs.
Built around a 64MHz Cortex M3 processor, it solves some of the short comings of a Linux based system – e.g. producing stable high-frequency PWMs in software. It also frees up the Raspberry Pi CPU to do other things such as running OpenCV to look around and make decisions.
The download page over at gertbot.com contains not only drivers and documentation but a couple of examples for various common robot configurations.
Voltage lines are all broken out individually on binding posts.
LM317-based voltage regulator. Using a 300 ohm resistor and a 2K ohm potentiometer, voltage range is 1.25-9V.
2 USB ports based on the TPS2513 from Texas Instruments. They can automatically detect what device is connected and adjust resistance on D+ and D- lines as needed. This means full compatibility and maximum charging speed on both Apple and Android devices. One of them is connected to 5v_STDBY, so that it works even when the PSU is off.
Pretty much everything can be fused. I left -12V out because it can only carry low amounts of current on most PSUs (mine is 500mA maximum).
Breadboard pin headers so that voltage lines can be connected to a breadboard using jumper cables.
Voltmeter headers in order to know the LM317 output voltage.
There is room for a 9W power resistor is your PSU needs it to stabilize output voltages. You can connect it either to the 5v rail or to the 12v one by jumpering the corresponding pads.
Status LEDs on fused lines and USBs so you can check if everything works fine.
Screw holes for standoffs.
Breaking Bad art because yeah, this is science, bitch.
The Raspberry Pi foundation just announced the new A+ model. It is cheaper, smaller and uses less power, than any other Pi out there.
With a smaller form factor, fewer ports and an improved audio output. The A+ model looks like a clear update. It also supports the new, wider, extension connector introduced with the B+ model, making it compatible with HAT add-ons. The retail price is set to USD 20 – a whole 20% cheaper than its predecessor.
I’m looking forward for trying my own A+. In the mean time, I’m curious about the actual power requirement figures, the quality of the audio and just how small it actually is.
The lowRISC project, based on Cambridge, is aiming to create an entirely open source hardware stack. This includes the SoC as well as the development board.
The design is based around RISC-V, a 64-bit RISC instruction set architecture. It supports GCC, LLVM and Linux, pairing the open source hardware with an open source software stack.
The lowRISC project is run as a non-profit organization. The team is built around a team with experiences from Cambridge University, UC Berkley, Raspberry Pi, Dreamwork, Radioscape, Google, OpenRISC and more.
This is exciting! The Raspberry Pi Foundation just announced that the Raspberry will be available in a new form factor – the SODIMM. The module will contain the BCM2835 SoC, 512MB of RAM and 4GB FLASH (eMMC). It will be available some time in June for about $30 in batches of a hundred units. For individual devices, the price will be slightly higher.
The target audience is producers of custom PCBs – which is great since there are a lot of hardware projects based on the Raspberry Pi – and at 200mA with video decoding and 3D graphics running, I bet there will be more.
In addition to all this, the foundation also announced the Compute Module IO Board. This is an open source breakout board providing access to HDMI, USB as well as large pin headers. It also provides a solution to power the board. The curious reader can have a peek at the schematics of the IO board, as well as the Compute Module.
For those of you who like to watch moving pictures, please enjoy the small preview below.
The EasyEDA project seems like an interesting project. They are developing a production quality EDA system, but with a different monitization model. The plan is to offer free, ad-supported, accounts, cheap, ad-free, accounts and premium accounts. The main revenue stream is not to come from these accounts, but from a prototyping service. So, if that service really flies, the tool might be free for everyone. One interesting part of the account plan is that one can upgrade the account not only by paying, but also by contributing howtos, schematic symbols, etc.
In addition to applying gamification and a different revenue model, they already have 75000+ schematic and 15000 spice libraries, so it looks as if the contents is growing.
I’m looking forward to seeing how this works out. It looks promising to me.