Seeed Studio March sale: Bus Pirate, USB Infrared Toy, ATX Breakout

Seeed spring sale

Seeed Studio shares our vision for the open source community. Since the beginning, Seeed has been our partner for project manufacture, sales, and shipping. That free us to concentrate on the fun stuff, but still make projects available to the community.

Seeed kicked off a spring sale on Mar 1st. Each week they’ll have a Flash Deal, with additional discounts during the whole month. If you are itching to pick up one of our projects, this might be the best chance. Seeed is offering these discounts themselves – you get a deal and we still get paid!

ATX Breakout Board Bench Power Supply
Flash Deal $9.5 (31%0ff) 2016/03/01~ 2016/03/07


Recycle an ATX computer power supply into a beefy bench tool that powers your projects. The ATX breakout board routes the -12, 3.3, 5 and 12 volt ATX outputs to screw terminals, each protected by a 1.25 amp resettable polyfuse. These four voltages cover many common electronics needs, there’s even a negative voltage (-12 volts) for op amps and audio projects. Get the deal here!


  • -12, 3.3, 5, 12 volt supplies @ 1.25 amp
  • 1.25 amp polyfuses with reset on each power rail
  • Indicator LEDs show that each rail is working
  • Power good and enabled indicator LEDs
  • On-Off button and control circuit
  • Optional load resistor included but NOT soldered
  • Open source (CC BY-SA)

USB Infrared Toy v2
Flash Deal $16.5 (15%0ff) 2016/03/01~ 2016/03/07


Use a remote control with your computer, view infrared signals on a logic analyzer, capture and replay remote control buttons, and play TV POWER codes. Get the deal here!

  • NEW: 100mA constant current IR transmitter with improved range
  • NEW: Infrared frequency measurement
  • NEW: Pin breakout area
  • Infrared remote control decoder (RC5)
  • Infrared signal logic analyzer
  • Capture and replay infrared signals
  • USB connection, USB bootloader for easy updates
  • Supported in WinLIRC
  • Open source (CC-BY-SA)

Bus Pirate v4
Flash Deal $29 (22%off) from 2016/3/15~2016/3/21

bus pirate

Bus Pirate v4 is a universal bus interface that talks to electronics from a computer serial terminal. Get to know a chip without writing code. Eliminates a ton of early prototyping effort with new or unknown chips. Seeed Studio is the official manufacturer and supporter of the Bus Pirate project. Get the deal here!


  • 256K program space, 4 times more flash than v3
  • Integrated, on-board USB (faster)
  • Data storage EEPROM to store settings
  • Software pull-up voltage selection: 3.3volt, 5volt, or external supply
  • 2 extra I/O pins
  • Multipurpose button

To see all our projects at Seeed, please click here.

Repairing the HackRF


Ramiro from did a repair of a HackRF One and documented the whole process on his blog:

I broke my HackRF One. I have no idea how, but I did it.
While testing a power amplifier I realized that there was not transmission at all. After checking the software, the connections and the power amplifier, I confirmed that my HackRF was broken. It was able receive but not to transmit. More precisely, I was not able to transmit when configuring the HackRF with medium-high TX power. However it worked when configuring the HackRF to transmit with low power.
A fast check in the schematics confirmed my fears: the power amplifier stage was blown.

More details at

Free PCB drawer moves to DEV site


Last week the “Free PCBs” link in the header began forwarding to a new Free PCB Drawer on the DEV site. Coupon codes from the three weekly giveaways can be used for anything in the Free PCB Drawer category with free shipping. Don’t see something you want? Coupons are also good for $1 off anything else in the store: SLA 3D prints, PCBs, component reels, pogo pins, etc.

Free PCBs are now part of an integrated shipment system and ship daily, instead of “occasionally”. Order status will be updated automatically…once the shipping interface is debugged later this week…

Old coupons are not yet working in the new store. Old coupons will be transferred by the end of next week and we’ll update you here.

So long Zencart, and good riddance! Working with Zencart was awful and it won’t be missed.

On a side note apologies for light updates the past week and a half. We’re struggling a bit to put the final touches on the new site. Tomorrow the first Harmony (pronounced Har-man-y) t-shirt will go up in the store. We also have to make a Hong Kong run to use internet stable enough bring up the Eagle/Gerber/3D print rendering cluster. If the cluster looks solid will be deprecated in a week, and we’ll only do major support for orders placed at the new site.

Next week a post about getting a Chinese driver’s license. The following week it may finally be time to drop the Expressway, we’ll see how it goes.

1st Annual ESP8266 Design Contest

esp8266-design-contest-badge-3 has announced the 1st Annual ESP8266 Design Contest:

Cash price awarded for 1st 2nd and 3rd place, of $1000 $500 and $250 USD an extra $250 onto these prizes if its open hardware or open software.

Both hardware and software projects can be entered. Hardware must have ESP8266EX SoC onboard, and software projects must support the ESP8266 platforms.

The deadline for submission is March 13th 2016. For more information and contest rules, visit contest page.


Mini CW Keyer / QRSS beacon v1.1


Marko Pavlin has designed a PCB for the CW keyer, he writes:

I designed dedicated PCB for the CW keyer. The project is very similar to the version made on prototyping board.

Here are the updates:
– I added relay and optocoupler for PTT control
– The “CW melody” selection pins have three jumpers for 8 combinations
– The audio output has 1W audio amplifier and RC at the PWM output (work to do in software driver for audio generator)
– USB connector is microUSB female which can be used with any phone charger

Project info at Mare & Gal Electronics site.

Open-source SWD programming adapter


Ethan Zonca from Protofusion writes, “After making the switch from AVR to STM32 microcontrollers, I redesigned my old 6-pin ICSP pogo-programming adapter for SWD. The new design allows programming with pogo pins or a small pin header soldered to the pogo pads for debugging, all with the same cable. The footprint uses surface mount pads only, so it can be placed on even the most compact board layouts.”

More info at project page.

ATtiny10 Mini Breakout Board

ATtiny10 MiniBreakoutBoard

Dan Watson has designed this very tiny breakout board for the Atmel ATtiny10. He wrote a post on his blog detailing its assembly:

This breakout board is for the ATtiny10 microcontroller. The PCB is 0.25×0.325″ and uses 0.050″ header pins. The board could actually be made smaller, but I ran into the minimum PCB size limit on OSHPark. Despite the tiny size, I was able to include a 100nF bypass capacitor, power LED, and a user LED on pin PB1. That pin is also the clock pin for the programming interface, so it flashed when the board is being programmed.

Project info at The Sync Channel blog.

App note: LED back light driving methods


Using pulse width modulation scheme for LCD back lighting an app note from Hantronix. Link here (PDF)

LED back lights on LCD modules are generally driven with a dc voltage through a current limiting resistor. This simple approach is perfectly acceptable for most applications. When the primary consideration is an extra bright display, the lowest possible power consumption, or a back light that can be controlled over a very wide brightness range another method is needed. The purpose of the paper is to describe this method.

App note: Temperature compensation for LCD displays


For over the normal range temperature, Hantronix presents a simple temperature compensation circuit to correct LCD contrast, Link here (PDF)

The optimal contrast setting for LCD displays varies with ambient temperature. For most applications this variation in contrast is tolerable over the “normal” temperature range of 0°C to +50°C. Most Hantronix LCD modules are available with an extended temperature range option which allows the display to operate from -20°C to +70°C. The changes in contrast are NOT usually tolerable over this wide a range of temperatures, which means a way of adjusting the contrast voltage as the ambient temperature changes must be provided.

As the temperature decreases the LCD fluid requires a higher operating voltage in order to maintain a given optical contrast. One way to provide for this is to give the user control of the contrast. This is a simple solution but quite often its not desirable or practical.