I've been looking through some cheap kits to purchase for practice (so that if something goes wrong which can always happen, it's less of an issue).
The cheapest clock I could find is $1.63 with shipping called "High Quality C51 4 Bits Electronic Clock Electronic Production Suite DIY Kits new" on Aliexpress.
Did anyone make this kit and were there any important issues that would prevent it being worth the low price?
Here's me trying to decode the description:
SCM procedures and test the inside, not another version of the program to provide electronic
No idea about this part.
"Power supply: DC3.7V-5.5V" Sounds pretty cool, a shame it's not CR 2032 compatible, but maybe with a step up or by using a cheap li-po.
Features:
1. normal walking, midnight show.
Does this mean the screen only lights at dark? Or simply that since screen is lit up, you can see it in the dark as well as in the day.
Not sure...
2. sub independently adjustable;
Not sure again.
3. Time seconds correction function.
Correcting seconds? Does that simply mean that an external oscillator is used to make it accurate, or perhaps some software "correction" built-in, or something entirely else?
4. You can fine-tune the clock speed of travel time, speed adjustable 0--9 default in 5th gear.
What? I really don't understand this one. Apparently, it has 9 gears and the 5th is the default.
Anyway, I guess this isn't the speed of timing? Time should be fixed of course to remain accurate, but perhaps it displays some different information, and you can change the speed at which the information displayed on the screen changes. Either that or something else.
5. The two-way alarm, and independently set the alarm off.
You never know, could be useful.
6. The whole point of the prompts, and you can turn off the whole point of open prompts.
Don't understand this one either.
7. The interface is equipped with a battery that can power down when walking. Battery can be guaranteed only when power is greater than 3V go. Uses two AA batteries, three AA batteries, or cell phone batteries can be.
Walking probably means working? That might explain point 1 as well.
8. The countdown function can be achieved within 99 minutes countdown, countdown to the end of the alarm.
Interesting, while not necessary (and makes things more complicated to use).
9. stopwatch function, stopwatch function can be achieved, may suspend stopwatch, stopwatch cleared.
10. Counter function can be achieved, can record keystrokes. You can also record the number of external pulses.
Pretty cool.
Below are the important features:
Kit Features: A dedicated clock using 0.44-inch red LED for display;.
B. imported AT89C2051 as the main chip;
C.1.6mm thick PCB FR-4 by military-grade sheet steel, Taobao most Plate
D. components small, simple installation, high success rate, not the debugger
E. accurate travel time, travel time error margin of error of about 3 seconds month.
Sounds really cool for the price as a practice kit that can actually be useful (a clock is always useful). Any tips or issues with this or other kits using this chip?
From:
http://www.atmel.com/Images/doc0368.pdfFeatures
• Compatible with MCS®-51Products
• 2K Bytes of Reprogrammable Flash Memory
– Endurance: 10,000 Write/Erase Cycles
• 2.7V to 6V Operating Range
• Fully Static Operation: 0 Hz to 24 MHz
• Two-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 15 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial UART Channel
• Direct LED Drive Outputs
• On-chip Analog Comparator
• Low-power Idle and Power-down Modes
• Green (Pb/Halide-free) Packaging Option
Seems interesting and definitely means that new firmware could be written by real experts. Not interesting in writing firmware for it though, neither have the equipment to flash it (or the knowledge).