Maintaining Raspberry Pi’s Wireless connection

Raspi-02I like to run my Raspberry Pi wirelessly, this can be done easily by adding a compatible USB WiFi dongle. With the introduction of the new Raspberry Pi 3, the built-in WiFi interface save us the need to find a compatible WiFi dongle or in the case where compatible WiFi dongle is not available, one needs to compile their own drivers for the WiFi dongles.

Even with compatible wireless devices using drivers that come with the official Raspbian distribution, I often experience the issue of periodic disconnection. This seems to happen at random interval, sometimes the connection is recoverable but often the Pi needs a reboot. This is particularly annoying if you setup your Pi as a server and your clients in your network cannot establish a connection due to the disconnected wireless interface. Let me share with you how my Pi servers maintain their own connections automatically.


802.11ac for Raspberry Pi 2

802.11ac-01I recently replaced my broken 802.11n router with a new 802.11ac router . The old router just stopped working for some unknown reason. To take advantage of the new 5GHz band and improved bandwidth this device offered, I also bought an 802.11ac dongle for use with my old notebook which only has built-in 802.11n WiFi. I’m happy with the performance and things were working fine until one day, something in my head tells me that I should run my Raspberry Pi 2 with this 802.11ac dongle too. I want to take advantage with the improved speed and bandwidth. The dongle comes with a driver disk, with drivers available for MS Windows, Mac and even Linux. Despite the popularity of the Raspberry Pi, you won’t find any per-compiled Raspberry Pi driver on the disk. Like many seasoned Linux users, you’ll need to “roll-your-own” driver. There are many success stories about building WiFi device drivers for the Raspberry Pi on the Internet, I would like to share with you how I get my 802.11ac dongle working on my Raspberry Pi 2.

Improving the T-962 Reflow Oven

When I got my first reflow oven, the T-962Infrared-IC-Heater-Reflow-Oven-T-962--340x270, I was a bit disappointed with the built-in firmware.  After I’ve made the several must do improvement hacks shown here, here and here. I’m still stuck with the badly written firmware and keep scorching many of my boards using the in-built profiles. There is a replacement controller available but it cost almost as much as the oven itself! Besides, the built-in controller has an ARM LPC2134 processor on board, it seems a waste not to make the most out of this 32-bit processor.

I was delighted to found that Mr. Werner Johansson of Unified Engineering has managed to improve the firmware of the T-962 Reflow Oven. His firmware has much enhancement over the original and by adding new thermocouple amplifiers, you can get more consistence results. Mr. Johansson makes use of the MAX31850 thermocouple amplifier from Maxim, which is a One-Wire device. His choice of this amplifier is due to the free pins available on the original controller. However, the MAX31850 comes in TDFN package. For those who has little confident to hand solder a TDFN package, I’ve a less elegant solution here. It does require extra chips and small modifications, but all the chips are available in either SO-8 or TSSOP package which even I can hand solder without any problem.