Troubleshooting

The most common problems experienced when working with the SB200 is listed below. All are to be considered normal and correct operation, even though it might require explanation to understand why the system (lack to) respond the way it does.

If you encounter problems that are not covered by the list report it to avr@atmel.com.

Table 1. Problems and Solutions or Explanations
Problem Solution/explanation
The values does not update when I push a READ button. Check that the "USB Status" in the lower left corner of the SB200 PC application is "Connected". If not ensure that the USB cable is connected, and that the SB200 is powered (green LED next to the DC jack should light up). Verify that the "Board" identification, also in the lower left corner, identifies the SB20x board correctly. If not, check that the SB20x smart battery board is correctly inserted. Ensure that the correct number of batteries are inserted in the battery sockets and that the "number of cells" jumper is mounted correctly (if the device board is identified correctly the LED will light up in the position where the jumper should be mounted. The smart battery AVR will not turn on after power off unless it get a "charger connect", which is a sufficiently high voltage from a charger. To do so, turn on the SB200 charger. This should turn on the Charger Active LED on the top-middle of the SB200. Try to read a command again. Check if the LED near the USB connector is constantly on (red or blue), if so, an unhandled error has occurred. The SB200 USB device must be reset, by pushing the left micro-switch on the SB200 - between the USB and the DC jack. Calibration of CC-ADC offset takes 20-30 seconds the first time the SB201 firmware runs. During the calibration the device board does not respond to any commands.
How can I test the AES Authentication? It just returns garbage when I push READ. You need to specify the correct AES key on the PC side to decrypt the encrypted reply from SB20x correctly. The key is "You cannot pass!". Specify the key, WRITE a 16 character string and now read back.
The SB20x responds to commands, but it is not possible to draw any current from it. If the load is active when the SB20x starts (whenever the discharge FET has been off, and are turned on). The integrator in the electronically controlled load will saturate and cause a short circuit current to flow for a short while. The solution is to disable the load for a while, and not enable it until the SB20x has enabled its discharge FET. The expanded parameters on the BatteryStatus command will provide this information.
Is it possible to change the auto-update refresh rate? Use the "Tools->Options" and set the desired timer interval.
I enabled the load to discharge the battery. It suddenly stopped discharging, and I cannot start the discharging again though the battery voltage of both cells is above 2.7V. This is because one of the batteries has been below 2.7V while discharging. The SB20x has disabled further discharging to protect the battery. To enable discharging, the battery needs to be charged shortly. Turn on the charger for a while.
The SB201 has "killed" on of my battery cells. It did not - the battery cell killed itself. This may occur if the battery cell's built-in protection is inaccurate - so that it triggers before the SB201 limits. Normally the battery can be brought back by turning on the charger. (During development you may load the battery too much, or (dis)charge more that the protection allows).
Set and clear buttons does not always respond. The PC software is busy fetching data from the SB200 (waiting for response). Normal response will be observed if auto-update is disabled. Alternatively, push the button several times - until it responds.
Can I use the SB200 with unprotected cells? At you own risk. Not recommended. (If you are a daredevil and remove the battery protection from the batteries shipped with the SB200, remember to wrap tape around the cells afterwards, so that the battery sockets does not short the cells)
The cell voltages are almost equal when the cells are fully charges, but are very different when close to fully discharges. This is normal. The battery cells used have different resistance, which is more evident when discharged. By enabling cell balancing the battery cells will have close to the same voltage when charged, which is important to be able to charge the batteries to maximum capacity.
I am not able to erase, reprogram or start a debugging session on the SB20x daughter board. If the firmware programmed in the smart battery AVR on the SB20x daughter board causes the device to enter power-off the programmer will not be able to reprogram the device. This can occur when the device enters poweroff very shortly after starting up (assuming that power cycling has been attempted); In this case the device turned off the internal regulator and the internal logic required for the programming tool to take control is off. It can be required to force the device on to get around this. This is done by connecting VFET to GND and VREG to 3.3V. When this is done the device is powered regardless of the state of the regulator, and erase and programming is again possible.