Member Since: February 16, 2007

Country: United States

  • "It's a bird!", "It's a plane!", "No, its Gorgo!"

  • "No, Mr. Bull, I expect you to die!"

  • "Say hello to my little friend!"

  • I am having a problem with this unit. When a battery is connected, no load is present AND the charge cable is disconnected, the battery is run down to almost 0v. This is terrible for (unprotected) Li-Poly cells, it ruins them and I have a couple of dead cells because of this.

    I have checked the UVLO jumper, its open, so one would assume that the under-voltage protection circuit would kick in and stop the battery from draining below 3.6/3.7v? From what I read and heard is that the booster is constantly on regardless of load and this is what drains the battery, BUT shouldn't the under-voltage protection kick in?

    I have had to add a switch to disconnect the battery from the charger on my projects when not in use. What am I missing?

  • The RHT03_PIN_DIR is used to control the RHT03_PIN's direction (input/output). Since this device uses a single I/O pin for communication, the code has to know when to send data and when to receive data.

  • Unprotected. These were pulls from laptop battery packs. I just weeded out the bad cells and added connectors, instant project batteries. The cells are not used in anything that does not have a current limiter and low voltage protector.

  • The title states 58 oz-in holding torque. But the description and datasheet state 48 N-cm, using the link provided by RobertC, converting 48 N-cm = 68 oz-in. Is the title a typo?

  • Ok, I have confirmation that this booster/charger will work with Li-Ion 3.6v cells. I have charged and discharged 18650's (or similar, 2600mAh) several times. I have also got it to work with one cell and two cells (in parallel, initially charged and connected to each other to level off; Be careful when hooking up cells in parallel and charging them!!

    My only problem with this board is the micro-USB connector. The connector is 'tight' and requires quite a bit of force to get a connector in and out. I found out the hard way how much force the connector can take before BREAKING OFF THE BOARD! Needless to say I was not pleased, but was able to re-purpose the board and use the second one I had bought.

    Sparkfun: Please develop a similar board that has a mini-USB connector and maybe something that will charge 4 cells? :-)

  • Yes, you are right, pulling the data pin high is to allow the RHT03 to pull it low and the RHT03 should do that approx 20-40us after the data pin goes high.
    I would try the following, connect pin1 to power (5v), pin2 to data pin (plus 1k resistor to power), pin3 no connection and pin4 to ground. Start with the data pin high and set low for no more then 20ms, then bring high. The data pin should show signs of activity. If not something might be wrong with the RHT03.

  • The initial LOW does not have to be exact, the datasheet states minimum of 1ms, I usually go 18ms because it seems to work for the DHT22, DHT11 and RHT03. The pull high and wait for 40us needs to be exact, the data sheet says 20-40us. This pulse needs to be within 20-40us long or the RHT03 will ignore the request.

No public wish lists :(