Stock check 1st January 2017: 33,157 items are on our shelves ready for despatchNagyon köszönöm a keddi, csodásan finom étkeket! A pacal most is zseniális volt! I’m planning to build a EEVblog-ish constant dummy load for battery and power supply testing. Dave in his build used a LCD voltmeter for the display. In the senseless pursuit of difference, I tried other display solutions including character LCD, graphics LCD, OLED, TFT, AMOLED, IPS, which resulted in several previous blogs but nothing ends up to be satisfactory. Along with the complexity grows exponentially from one  solution to another, I slowly start to feel the importance of KISS concept, keep it simple stupid. All I need is just a number display, nothing fancy, nothing pricey, nothing takes my attention away from the analog circuitry. I decided to go back to the basic 7-segment LED display. “Simplicity is the ultimate sophistication”, how elegant it is! I ordered several LED voltmeters from a taobao seller.

It costs RMB16 each, about US$2.6 excluding shipping. The original design was for battery measurement on scooters. The advertised accuracy is 0.2%, which turns on my bullshit detector immediately. So the first thing I did after receiving it, was “don’t turn it on, tear it apart”. The manufacture did not scratch off the markings so the schematic can be easily traced out. The heart of the voltmeter is “STM8S003F3P6”, a 8-bit MCU with 16MHz clock and 8K flash by STMicroelectronics. Datasheet shows this MCU has built-in 10-bit ADC. Driving 4 digits 10000 counts with 10-bit ADC is definitely overrating. While somebody may argue that ADC resolution can be increased using oversampling, without proper noise injection circuitry I cannot confirm it actually works. Furthermore the MCU does not have a dedicated ADC reference input. Supply voltage is used as reference. As the display needs to scan each digit continuously, supply fluctuation is inevitable. How to maintain ADC accuracy with changing reference?

The original designer may have considered this problem initially. He/She added D9 (TL431 2.5V reference) and connected its output to analog input AIN6. awolnation backpackSo before measuring the input voltage at AIN5, 2.5V at AIN6 can be measured and then AIN5 calculated relatively. jasper backpack billabongHowever D9 was not populated on the board I receive.kbs backpack simple I was in the verge of desolder the LED and suddenly an idea bumped into me: why not reprogram this module and use it as a sole display? kriega backpack saleBy doing so I can offload the LED driving task to the STM8. The original designer has reserved footprint for a 6-pin connector with SWIM programming/debugging interface and TX/RX serial port, reprogram should not be too difficult. 

A second thought is that it would be even better if I can emulate a popular serial LED module so that all existing codes can be used. The “Adafruit 4-digit 7-segment LED backpack” is soon identified. Ladyada did some remarkable work to develop Arduino library and wrote a tutorial for it. Make something compatible with her work is my honor. However the Adafruit LED backpack is using I2C interface. The hardware I2C pins on the voltmeter is already occupied for driving LED, which means I need to bit banging I2C slave protocol on GPIO pins. There are many online resources about I2C master emulation, but I2C slave emulation is very limited. The best one I found is an article published by TI “Software I2C Slave Using the MSP430“. It depicts an entire state-driven process of interpreting I2C signals, together with some assembly code for MSP430. To help understanding I made a flowchart, and  rewrote the library using C code. Some notes to potential users:Ted Baker Announce SS17 Collection for iPhone 7 and 7 Plus

SCUF Elite Xbox One Wireless Controller Samsung Explains Why The Galaxy Note 7 Exploded! HealthView Gives You A Better Look At Your Apple Health Data iPhone 8 Concept ’10th Anniversary iPhone’ Bought To Life [Video] AllAccessoriesAccessoriesAppsAudioBags / BackpacksBrowser ExtensionsCamerasCompetitionsComputersControllersDAC'sDocks / Stands / MountsExternal BatteriesFeaturesFitnessGamesGamingGroomingHeadphonesHeadphonesHome TheaterHow TosLaptopsMedia Hubs & ReceiversMicrophonesMiscMobileMouse & KeyboardsNetworking & WirelessNewsOtherPen TabletsPhone CasesPhonesPhotographyPrintersRange ExtendersReviewsSecuritySmart HomeSoftwareSpeakersSystemsTablet Cases SHARKK Portable Bluetooth Boombox Speaker KitSound Cayman 2.1 Bluetooth Speaker Sony MDR-10RBT Bluetooth Headphones Veho ZS-2 Sports Headphones iT7 Mini Bluetooth Speaker Sonos Play:1 Wireless Speaker Lava BrightSounds Bluetooth Speaker Jaybird X2 Wireless Headphones Scuf Gaming Launches Accessories and Controller Customization for the Xbox Elite Wireless Controller 19th December 2016

Keeping Tabs on Christmas TV! – Vodafone 19th December 2016 Christmas Gift Guide: iPhone 7 Cases 23rd November 2016 SCUF Elite Xbox One Wireless Controller Controllers Corsair Raptor HS40/HS30 7.1 Gaming Headset SCUF Infinity1 Xbox One Controller Scuf Gaming 4PS Controller NETGEAR Nighthawk AC1900 WiFi Range Extender (EX7000) NETGEAR EX6200 WiFi Range Extender NETGEAR Powerline 200 Mini NETGEAR R6250 Smart WiFi Router Anker PowerCore 20100 Power Bank External Batteries iWalk Link 3000m Portable Power Bank Wacom Bamboo Pad [REVIEW] 16th May 2014The requested URL /content/westfield-corp/gb/www/products/bags-luggage was not found on this server. Sort by: best match Sort by: lowest price Sort by: highest priceIt is a discontinued product, displayed only for reference. The Megrez 72 FD Doublet APO is here to fit all your needs! The 72mm ED Doublet operates at F6 and is a true multi-purpose tube assembly.

Excellent mechanics fit and finish, Crayford 2-speed fine focuser, super-high transmission multi-coating, optional white ABS backpacker type carry case. It's fast focal ratio makes it your ideal travelling set-up for travel astrophotography, piggybacking or as a spotting scope. ED glass doublet air-spaced, in CNC machined ultra-high precision lens cell. Each lens is Fully Multi-Coated with a special super-high transmission coating (STM Coating) on all surfaces. Fully baffled to block all extraneous off-axis light rays and prevent glancing reflections, increasing overall contrast. 72 mm clear aperture. Nothing Left to Chance Perfect for EAZY-T Alt-Az Mounts. You can slide it directly into the mount without a dovetail plate if you like. Pure William Optics quality fit and finish: powder-painted white CNC-machined aluminum tube Drawtube travel length 81 mm with graduated scale. Retractable dewshield, smallest size ever and enhanced portability!