Question about I2C-USB and Servo Controller with BS2p

[johncl]

Hi, I have purchased the I2C-USB and SD21 Servo Controller among other things and I have a few questions related to this. I'd will at first use the USB-I2C to control all I2C devices since my robot is using a full Via Epia motherboard. However, I might consider adding a BS2p at a later stage to automate some sensor gathering as well as using the extra pins to add other non-I2C sensors (e.g. temperature, humidity, and some bumper switches). My questions are then:

Will the I2C-USB coexist fine with the BS2p or will their communication on the I2C bus cause collisions?

Is there any way I can send a command to the BS2p through the I2C-USB adapter to e.g. retreive data from it (last readouts etc) or send commands to it? I would then be able to avoid the RS232 communication to the BS2p alltogether, which would be nice (although having serial com with it is also easy).

Thank you.

[Gerry]

Hi, I have purchased the I2C-USB and SD21 Servo Controller among other things and I have a few questions related to this. I'd will at first use the USB-I2C to control all I2C devices since my robot is using a full Via Epia motherboard. However, I might consider adding a BS2p at a later stage to automate some sensor gathering as well as using the extra pins to add other non-I2C sensors (e.g. temperature, humidity, and some bumper switches). My questions are then:

Will the I2C-USB coexist fine with the BS2p or will their communication on the I2C bus cause collisions?

Is there any way I can send a command to the BS2p through the I2C-USB adapter to e.g. retreive data from it (last readouts etc) or send commands to it? I would then be able to avoid the RS232 communication to the BS2p alltogether, which would be nice (although having serial com with it is also easy).

Thank you.

Unfortunately, this will not work. Like the USB-I2C, the BS2p is an I2C master only. It cannot be a slave and therefore cannot be controlled from the USB-I2C, or co-exist on the same bus. If you can do without the local processing of the BS2p, you can use a GPIO14 to give you some extra I/O lines. Its a lot cheaper than a BS2p as well.

[johncl]

Ah yes, thank you for the tip. The GPIO14 pic seems to be just what I need to get some digital and analog lines interfaced through I2C.

But I guess it will be hard to interface something like the Sensiron SHT1x Temperature and Humidity sensor?

http://www.parallax.com/detail.asp?product_id=28018

It seems to base a lot on an intricate array of sending data bits and bringing the clock high and low to communicate. I guess I should be able to do this from a computer also unless there are some strict timing rules that needs to be followed.

Maybe I should just leave it at a simple temperature sensor at first which can be read through an analogue pin on the GPIO14.