For just a single 3-5mm panel led could you use an op amp and a few resistors? Might fit on a small board ~ 15mm.
Edit-Like this maybe Matt could help you with the board
For just a single 3-5mm panel led could you use an op amp and a few resistors? Might fit on a small board ~ 15mm.
Edit-Like this maybe Matt could help you with the board
seems these days programmable drivers offer a lot of flexibility…it might be possible to program one of these drivers to get the functionality needed
re. Star firmware: STAR Firmware by JonnyC - Source Code and Explanation
Looked up the data sheet on the 3.0v voltage monitor linked by Helios and found this schematic
Looks pretty simple to use for just one led.
Thats whats so nice about them. Tiny, easy & uses very little current (0.5 uA typ). Also don’t need to be able to program chips. Just connect the voltage monitor chip, indicator led & resistor (aim for <50mA led current).
Haven’t ordered one yet since the attiny can do low voltage detection.
I ordered one weeks ago, I think it is the smallest, with digits
Whoa that is small - size of a sim card. I looked around - cheapest is $5 shipped for these (vs $1.40 for the bigger guy), quite a jump in price for tinyness.
Interesting why the red is always cheaper than green/blue version - easier to build due to Vf probably?
I like the readout style over the lights. It's larger, but if I can fit it in, I will use the readout style. I don't really need a low voltage warning, I just think a readout of voltage would be kind of different.
Cheapest I could find:
RED:
http://www.ebay.com/itm/0-28-Digital-Panel-Meter-DC-2-5V-30V-Red-LED-Power-Monitor-Lithium-Car-Motor-/251303490316?pt=LH_DefaultDomain_0&hash=item3a82daf30c
Starts as low as 2.5V
YELLOW:
http://www.ebay.com/itm/0-28-Digital-Voltmeter-Power-Monitor-DC-2-6-30V-Voltage-Panel-Meter-Yellow-LED-/390625402570?pt=LH_DefaultDomain_0&hash=item5af3169eca
Starts at 2.6V
Found some better prices now, $1.90 for red to $2.46 for blue:
I don’t think they get cheaper than these. I’m probably going to grab some afterwards. I already have the bigger version in many colours, and I must say the blue LED is the most beautiful - kind of classy, expensive looking.
Dang! Making em smaller and smaller!
The numerical LED blocks are standard size. Three digits is too wide (>20mm). Maybe replace it with two digit block if one decimal place resolution is acceptable?
The ones from gigibaobao are better quality than FastTech, with trim pot and work to lower voltage, but still too big.
Another idea, maybe use two or three of the kind Helios posted set to different voltages?
It would take an OLED monitor this type of PLX
http://www.plxdevices.com/product_info.php?id=MOBLLEGION055
What do you say to use the monitor like that?? I think you can try!
definitely finding the lowest prices!
http://www.fasttech.com/products/0/10007685/1665901-vstar-s7-0-6-oled-variable-voltage-apv-mod
I never thought of OLED! Gotta research that!
look forward to hearing from you!
I ordered a few of them from Fasttech and they won’t read voltage until it rises above about 3.3 volts. They do work great for RC lipo monitoring & portable solar cell and checking batteries in the field with out lugging a huge Fluke meter.
That’s James Bond kinda cool!
Here is a “tindie” build with an OLED display…perhaps something can be modded up
Note: Also works with the VA Tester This allows you to monitor other voltage sources from 0-26VDC and 3.2A and use the OLED Backpack and it…
Price: USD 49.00
Adaruits
These displays are small, only about 1" diagonal, but very readable due to the high contrast of an OLED display. This display is made of 128x32 individual white OLED pixels, each one is ...
Price: $17.50 USD
128x32 SPI OLED graphic display
Even smaller
ER-OLED0.83-1W is 96x39 pixel,0.83 inch small oled display manufacturers,serial,i2c interface,ssd1306 controller,used for mp3,secondary screen,white on black.
Price: USD 3.54
96x39 Pixel 0.83 inch Small OLED Display
Smaller still
64x48 dot matrix 0.66"oled display module with datasheet,price,pinout,arduino,serial spi interface from china manufacturer supplier.
18.4 x 18.1mm, that last one is really cool but how the heck do you program it for a voltage readout?
18.4 x 18.1mm, that last one is really cool but how the heck do you program it for a voltage readout?
That is why the adafruit has the control board breakout
needs a tiny circuit to run it…and firmware
18.4 x 18.1mm, that last one is really cool but how the heck do you program it for a voltage readout?
I think you could bitbang i2c with an ATtiny. You could take the voltage reading using the standard divider method on the ATtiny and then output it to the display. You’d need additional space for the larger firmware - probably an ATtiny85 with Arduino would be the most straightforward way to build it.