Probably most of you know that ESP8266 can be used as WiFi connectivity module or as stand alone programmable device with same internet features. Anyway for serious applications probably it is best to use it as module along with another microcontroller. Electro-labs have shared pretty neat development board based on PIC18F microcontroller which comes with buttons, LEDs, LCD, FT232RL based USB connectivity and integrated ESP8266 module.
WiFi module can be controlled by microcontroller or directly from computer via FT232RL chip. Normally ESP8266 module is controlled with AT commands sent from microcontroller or from computer terminal.
Jordan started this binary watch project to gain more experience in programming PIC MCUs for low power applications. But it turned out pretty successful that after wearing it for about a month he started selling them for everyone.
As we mentioned, binary watch is based on PIC18F24J11 microcontroller which drives bright LEDs on display for each binary digit. Having bright LEDs installed he was able to dim them and this save power without loosing brightness. Watch is powered by CR2032 coin cell battery which is enough for 3 months of usage. Special care is taken to make watch as low power as possible by combining several MCU sleep modes. He found interesting solution to watch clasp. He used same programmer ribbon cable and secondary non electrically connected header on other edge of board. It really looks great and there are no redundant parts.
This wrist watch, made by Elia, is a binary based wrist watch i.e. displays time in binary digits and is small in size. The yellow-color LED’s for the digits perfectly suits the watch and also is compatible with the OSHPark PCB, which is a custom PCB-board manufacturer. Another interesting fact about the watch is the strap which is paracord bracelet along with a buckle. The steps to make the buckle are easily available on the internet. The watch is powered by the PIC microcontroller which comes with a SSOP package.
Along with the PIC, it also has an on-board ‘real time clock’. Moreover, it also features a sleep mode in which there is no display and consumes only 150uW of power. There can be additional power saving by pulling the remaining pins to either VCC or GND. However this functionality is not yet available in the current PCB. Overall, the watch is really good and a must try for those people who have just started learning the PIC microcontroller. Moreover, if you are considering to make this watch yourself with the same schematics, I would advise you to cover the PCB and the LED’s with a good quality glass.
LEDs have an effectiveness higher than that of just about all the customary lights and hence are used almost everywhere. The system in the article is basically a driver that can control two groups of white LED’s. The LED’s are operated in PWM mode using a suitable timing to obtain the required colour. Moreover, the entire system can be operated wireless at a frequency of 433MHz using amplitude modulation. On the receiver die, it’s a powered by a PIC16F876A which act as a decoder for the received amplitude modulated signal.
The decoded signal is then processed by the controller to generate the required PWM signal for the two independent group of LED’s. The group of LED’s are driven by using a common source transistor and therefore the design is only compatible with common-anode LED strips. Another interesting thing about the procedure is the self-learning method it uses to learn the required codes to change the level of brightness for both the warm and cold type of LED”s used in the project. The entire schematics along with the code and the working are available on the website.