Ethan Zonca of Protofusion writes:
While developing the Luma RS485-networked LED driver we discovered a need for a small and inexpensive USB to RS485 adapter. We designed an adapter with a FTDI basic UART chip (FT230XS) and an inexpensive TI differential receiver (SN75176). Our small selection of parts brings the cost down to just over $5 for one adapter.
Open hardware USB to RS485 adapter - [Link]
a cool project by Mats the OSUS Master board. Files available on Github :
A long while ago I wrote about that I might make a series of boards for easier testing of the open USB stacks. Testing all different version of mcu’s and crystal speeds to make the right #defines and linker maps for the firmwares can be a bit tedious.
OSUS will make life a bit easier by removing most of the parts required on the boards to be tested down to a master board. The test-boards basically only need a decoupling cap two and a 14 pin 0.1″ pin header – that’s it.
OSUS – Open source USB Stack test board - [Link]
By Steven Keeping:
Power management in portable devices is one of the toughest challenges faced by electronic engineers. The consumer demands instant response from their device, lots of functionality, and a large, bright and colorful touchscreen. Moreover, many of these portable devices now incorporate wireless connectivity that places further demand on the cell. And yet, the user expects the battery, a sensitive lithium ion (Li-ion) cell that requires careful recharging from a number of sources including USB sockets, to last for at least a day and then refresh quickly.
Designing a power management system to meet these conflicting problems is tough. However, there are some proven design techniques that help extend battery life. Moreover, the key semiconductor vendors have made life a little easier by offering power management units (PMUs) that integrate some, or even all, of the functionality needed for the efficient power supply of portable devices.
Design Techniques for Extending Li-Ion Battery Life - [Link]
Brian posted an article describing how he designed and built his business card:
A business card should represent a person’s expertise. My expertise is in creating unique circuit boards, so to celebrate this I wanted to create a USB thumb drive circuit that contains my resume and contact information. This was also a great way to experience coding for USB applications using the Cortex M series of microcontrollers. As a side note, I have done other projects with Cortex M including a simple serial relay and a USB keyboard emulator, but this is the first one that is exciting enough to write about.
Business Card version 2 - [Link]
Frank Zhao posted his STM32F4 breakout board [via]:
I really like the STM32 family of ARM microcontrollers. This breakout board is a narrow design that fits perfectly on a breadboard. Every pin is accessible. It has USB, a reset button, and a bootload button. The chip itself has a permanent USB bootloader that is activated by the bootload button. This means that no equipment is required to program this microcontroller, no expensive debugger, nothing at all except a USB cable.
Design files are open source and can be downloaded, there is also a short video about the bootloader and more instructions
I am also giving away blank PCBs to those interested (see “giveaway” on my page), Seeed makes more than I need, every single time
STM32F4Stamp, a breakout board for STM32F4 - [Link]
I grew fond of NXPs new LPC800 Cortex M0+ microcontrollers. I designed a small breakout for the LPC812 TSSOP20. This is the second revision. It includes push buttons for reset and activating the serial bootloader. The board has an integrated 500mA 3.3V LDO to supply both the MCU and connected devices from the USB port. The four pins on the top side (5V,RX,TX,GND) can be used to connect a cheap USB to serial adapter and program the device via the internal bootloader using FlashMagic.
LPC812 Breakout board - [Link]
FT230X charger detection investigation. Baoshi writes:
I bought some FT230X (FT230XS) USB-USART bridge chip recently for a new design. FT230X is not only cheaper than the traditional FT232RL, but also offers a new fancy “USB charger detection” function. This interests me because I’m quickly running out of desk space and power socket. I wish the new device to be solely powered by USB and/or battery.
FT230X charger detection investigation - [Link]
“Power bank” or a mobile power supply with a USB output can contribute also to your undisturbed work.
Nowadays already almost every battery-operated device with a USB port has a possibility to be operated or recharged through this port. Whether it is a smartphone, external harddrive, various modems, dataloggers and many other specialized devices, almost all of them can be powered/ recharged also from a USB port from an external mobile power source -”Power bank”.
In respect to the fact, that there are still more devices with this possibility, we incorporated to our stable stock offer two types of these power supplies – B110 and B120 from a renowned company Apacer. They differ mainly by a capacity of an in-built battery (4400/ 6600 mAh). B110 has one USB connector with a max. output current of 5V/1A, while a bigger type – B120 features two USB ports with a max current of 1,5A/1A (max 2.1A both ports simultaneously). Both Power banks can be recharged through a micro USB port by means of a supplied short USB cable enabling recharging for example from PC, USB adapter or from still more used wall USB outlets, which are becoming a common part of modern buildings installations, on airports etc. The same micro USB/USB B cable can be consequently used to connect a device which we want to power/ recharge (through an “OUTPUT” connector). A small complement of both types is a 5mm white LED, thus B110 and B120 can serve as a small torch with a long hold-off.
Apacer B110 and B120 – Power banks not only for your smartphones - [Link]
The Arduino compatible board to take your projects beyond your home and garden. Anywhere your imagination takes you.
Prototyping should be rapid. Putting projects together should be as easy as clicking together lego-like building blocks. SODAQ makes it so. SODAQ is a multi-feature microprocessor board that lets you connect sensors and devices to the internet, quickly and with no fuss. It’s designed for connecting things efficiently, running off-grid with built-in, ready-to-go solar power:
Getting data off a device is only half the story – it needs to go somewhere. We designed the SODAQ system to be able to communicate from anywhere, with a GPRS module and all the control code for it included from the start.
It takes the Arduino prototyping concept, makes it simpler, and extends it. No breadboarding or soldering required, but with plenty of memory, sockets, solar panel and battery control, and extra features, all on one board.
The board has built in sockets for Grove modules; a realtime clock; extended flash memory; USB on-board; and the Bee socket can take any WiFi/RF/XBee or other compatible plugin for communications instead of our GPRS module.
SODAQ: a lego-like, plug-in, rapid prototyping board - [Link]
This video by Ray Wang demonstrates HID-class USB serial communication for AVRs using the V-USB library:
Serial communication is helpful for debugging and checking sensor values, and HID-class means it can work on all operating systems without driver installation. This is useful for many software-only USB projects such as based on ATmega328 or ATtiny45/85. To receive and send messages between the device and host, I wrote an HID serial monitor, similar to a standard serial monitor, using Processing.
HID-class USB Serial communication for AVRs using V-USB - [Link]