Smart watches with their own hands for 1500 rubles



This story began with the fact that after reading posts tagged DIY, I decided to get a set of MC + Evaluation Board. Googling, I learned that the cheapest is in charge LaunchPad from TI. Without hesitation, he went to the store for her, and rushed ... like all the flashing LEDs were first, then connect the display from Siemens CX75, etc.
Soon I got tired of doing something just like that, without a purpose, in order to do that. So the idea to create for itself a gadget that I use constantly.
For details, ask a cat.

Usually I walk down the street with headphones and can not hear the phone ring, and a bunch of phone pocket + Case + + = walking vibration is not felt. And I thought to myself gadget: the informant about sms and calls in the form of hours / bracelet. Again, the idea is not new and in stores like a bunch of stuff, but would like to, first, do it yourself, and secondly, still cheaper to obtain. The first pancake, as they say, lumpy:


"I do not know my clock time is not shown.» ©
The composition is simple: MK, BT, diodes, voltage, vibration motor, rechargeable battery, the case of the old clock. For it has been written application for android, program for small and MC. Miracle of the beast, which had already 6 months that I have rescued more than once.
What makes the program for android: Connect to BT clock, send "1" - Connect passed, start the service and listen to incoming SMS and calls. At reception of it, send to BT event ID "2" - SMS, "3" - a call.
What makes the program on MC: when receiving a character with BT («1", "2", "3") includes the definition of the sequence on / off display and vibration.
About any power saving mode when I did not think, and that the regulator operates at voltages of 3, 6 - 6 the same as that forgot to find out. As a result, a single charge lasts for akkuma working day, provided that the "clock" permanently connected to BT.
About three months ago I decided to take up this idea thoroughly and add functionality that is not enough: full clock, caller name display, text and sms sender, you can not flash. With the last thought will have problems, because MK reflash for Spy-Bi-Wire interface, and pull the pin 3 output body did not want to, but then read in the datasheet that MK has a mode bootstrap Loader (BSL), allows you to flash it via UART interface .

Insides
That took me out of parts that had to buy:



First wanted to put in the cabinet MK QFN, but then refused, and took the body tssop28. It is easier to breed, since under the body still has a place.
Name details
Purpose
Cost
msp430g2553ipw28
microcontroller
60
lir3048-lby2
battery
77
ds1337u +
Real Time Clock
78
ADP3338AKCZ-3.3-RL7
stabilizer
124
CP2102-GMR
USB-UART
84
MCP73831T_2ACI_OT
charging li-ion, li-pol
54
HC-06
bluetooth
120
LCD nokia 1202
screen
33
Total: 630r.

All items purchased in the city, except for BT - it ordered from China, if you buy in the city can be found for 350r.
The rest: mini usb, buttons, vibration motor taken from the old device; quartz and passives found in the bins homeland. If you buy small things that will come out on the strength of RR 300.

Details are, what's next? Then going to the layout and write programs for MC. Abandoning Energia, I switched to CCS 5.3 free version with limited code 16kb which is enough, given the amount of memory IC (16kb). In MK involved: 2 and timer WDT + in interval timer mode, HW I2C, ADC10, BSL, FLASH. Particular attention was paid to the consumption of the device. As a result, 30 mA at full load (BT is not connected, the MC in the normal mode, the backlight to the maximum), 8 mA in standby (BT connected, MK in a low consumption lights off) and less than 1 mA-only clock (BT off , the MC in the low-consumption lights off). Capacity akkuma 200mA, so that a single charge lasts for a day or more. Simultaneously with the programming MK, modify the program to android, namely when an incoming call, searches for a matching number in the phone book and if a match is found, replace the name and number on the ship BT. And when you receive a sms send text messages, and more.


Fee
After writing the program and test the viability of the collected layout, I started to PCB layout, etching, tinning and soldering.














  1. On the whole board took 6 jumpers, 5 capacitors, resistors 8, 1 LED. Turn ... works!

    Housing
    Perhaps it was the most difficult. Dremel, plexiglass, dichloroethane, pasta goyim: hell of a mix ... I'm not particularly describe the process of construction of the body (and I forgot to make the photo). 2 layers of 6mm plexiglass at the bottom of the case and 2mm acrylic and glass protecting the screen from the old camera down on the top. During vytachivaniya body raised the question of fixing hours on hand, conventional watch straps were too zaparno their retention mechanism, so I bought here for a 350r .:



    A couple of through holes in the case and a strap hole is ready. Case has really not very good, but the functionality of hours it has no effect and fully perform its functions.

    Here is a video work:


    And finally sign for all the functionality of my watch:
    • display the date and time as the main function;
    • update the date and time from your phone;
    • Changing the date and time manually;
    • On the BT connection to the Android phone;
    • Power Off BT on loss of communication to conserve battery power;
    • display the battery charge;
    • to inform you of an incoming SMS with text output, and the sender's name on the screen;
    • to inform you of an incoming call out the name of a caller on the screen;
    • display the text typed in the program for android;
    • change display settings (brightness and turn off the backlight time, the contrast of the screen);
    • you can not flash the device.
      Conclusion
      While I was busy with this watch, I suspect that such an article already publish Habre, but as it had passed.
      Hours wear for a week, sometimes correcting software glitches and bugs. Recently added the ability to reset a call.

      I hope this post will inspire you to do something useful.

      P.S. I look forward to questions and comments!

      Source: habrahabr.ru/post/218495/

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