JY-MCU 3208 Lattice Clock HT1632C Driver with MCU & Support Secondary Development

Pros: Out of the package, it behaves as a clock/calandar. When powered up with a 5VDC source, the unit will display the time then shortly afterward scroll the date. The time and date can be set by pressing the top button to go into settings mode, then pressing one of the lower two buttons to raise and lower the setting. When in standard display mode, the brightness can be raised or lowered using the two lower buttons. The on board microcontroller is an ATMEGA8L clocked with a 32.768KHz crystal. There is no bootloader and the device must be programmed via the ISP connector on board if you wish to re-program it. The lock bits are not set therefore the code can be read off the device if one is so inclined. An LM34 or LM35 Temperature sensor can easily be mounted where the DS18B20 would go. All that needs done is a resistor must be removed and AREF must be set to VCC as it isn't electrically connected to VCC. I have done this and it works great. TX/RX is broken out in the 10 pin ISP connector.

Cons: It would be nice if DX would have at least provided a link to the source code on the mcu. It would give people an idea of how to drive the HT1632C driver if they didn't know. There is no reset button and the reset line is not wired as an Arduino with a capacitor so most likely it would not autoreset if attempting to program it serially via a bootlader (if one were installed).

Other: For the money, you can't go wrong. This makes a great little development board for an LED matrix.

Pros: Nice module with a nice LED driver. Comes with an ATmega8 just waiting to be programmed by you. Includes an ISP header. There are spots on the board to add several components like a temperature sensor or a battery buffered real time clock. Three buttons.

Cons: The original clock software is a matter of taste, but the date display with chinese symbols is a con for most. Bought it for programming myself anyway. Mine is off by 6.5s per day. Some software adjustment is needed to compensate. Lacking documentation. It took me a while to finally get my program working. See the forum posts for my demo c-code. LEDs are organized in rows within each 8*8 matrix, which adds to software complexity. Also some easily accessible connectors for own expansions would have been nice.

Other: Nice module for those used to micro-controller programming. Now trying to find a project for the second module I ordered :)

Pros: works on first sight all components soldered nicely power connector onboard absolutely no soldering needed to work ISP header Atmega8 onboard begins autoscrolling after some time (SW) brightness adjustable (SW) provision on the board for an RTC clock with battery+crystal provision on the INT1 input on the atmega for possibly IR receiver

Cons: well, the month/day character is in chinese, but as the unit is from China, I'm not sure if this is a con; next time maybe just use a dash, ok? no voltage regulator! caution, you will fry at least the mega8 with a cheap wall-wart! no documentation not for beginners leading 0 in time mode not blanked out, ex. 09:22 (SW)

Other: Positive for the price, definitely _worth_ _every_ _cent_, in shops the individual components would cost double that. Negative for the lack of any kind of documentation, the PCB design files would help to know what pin of the atmega is connected where.

Pros: Works. Arduino drivers available, but layout of matrix differs from sure 3208 matrix and minor modifications are required. Performs well and is relative cheap.

Cons: Build-in application (clock) is useless, since oscillator quality is not good (time differs several seconds in a day). Be careful with voltage (5v) since board has no regulators and over voltage will kill it.

Other: Decent led matrix, simple to utilize, works well. Build quality decent. Good deal for hobbyist!

Pros: Cheap, hackeable and cool. I can make some fun stuff only adding an accelerometer and replacing the atmega8 by an Atmega 328 with Arduino bootloader. You can see a cool hack at http://www.radikaldesig.com/2012/08/22/sistema-de-particulas-en-matriz-led-con-acelerometro/

Cons: Could include a 5v Regulator to prevent possible over voltage from people without electric knowledge

Other: We need more cool stuff!!!

Pros: - Working out of the box. - Simply connect 5V to the Jack and it can works. (I connect a USB cable with a Jack on the other side and power it from my xbox360) - Really bright when at Max. - Digit are Big,

Cons: - Not enough instruction to change the built-in code. - Need a external programmer device to change the Chinese code.

Other: DX should link to the source code so we can change the language inside. When programmed with another code (clockmtx.c) the time is more accurate. This is a great product and will buy another one if needed :-)