Hi everybody We designed a shield to read analog data from infrared sensors and to power an audio class D amplifier. We use the 5V PIN as output to power the sensors and the audio amplifier (consumption < 800mA). With the Dual no problem, we can start the board computer with android, we can read the analog datas and we can use the amplifier. But with the Neo there are a issue to start the board computer. It does not boot when the shield is connected. Has anyone ever had this kind of issue ? Thanks
I have read it before that the Neo is very critical in power usage during startup. If the 5V is drawing too much current it will not boot. Workaround would be to power your shield separately from the Neo or have it delayed in drawing high currents.
Hi Waltervl Thanks for your answer. I tested by powering my shield separately with an external DC DC converter (12V to 5V) it works well. But I have already ordered several shields Is there a software solution ? What solution I can apply to make the delay in drawing high currents ?
I don't know, I thought it was your own design so you would be able to design the delay yourself Perhaps switch on the amplifier later with some delay circuit or triggered from a pin from the Neo? The amplifier looks like the highest current demanding device.
Its not wise to expect the 5v output to probably drive more than 500mA (it may be less) provided by the on board regulator. The internal 5v rail supplies a number of the components and your load current is disrupting that. You can review the schematics to see how the power rails are managed. Ideally for your level of load it makes sense for you to use another power source.
