Search found 164 matches

by viswa
Mon Mar 07, 2016 2:17 pm
Forum: Wearables
Topic: SPI settings
Replies: 1
Views: 2688

Re: SPI settings

Hello,

I hope you are referring to Xadow Mainboards(Which is based on ATmega32U4). Yes, the SPI documentation describes the API used for SPI communication. Please refer the examples mentioned in the page writing driver for your BM019 NFC reader.

Thanks and Warm Regards.
by viswa
Thu Mar 03, 2016 5:17 pm
Forum: Grove
Topic: MQ2 Gas sensor Intro
Replies: 11
Views: 6163

Re: MQ2 Gas sensor Intro

Using RS/R0 value and matching to the graph is the closest approximation that can be got without using external calibration.

Yes, these values depend on temperature and humidity.
by viswa
Thu Mar 03, 2016 12:57 pm
Forum: Grove
Topic: MQ2 Gas sensor Intro
Replies: 11
Views: 6163

Re: MQ2 Gas sensor Intro

The Rs/R0 seems to be correct. BTW, the wiki only provides a method for approximate measurement. The measured value needs to be matched with the graph. "According to the graph, we can see that the minimum concentration we can test is 100ppm and the maximum is 10000ppm, in a other word, we can get a ...
by viswa
Thu Mar 03, 2016 12:18 pm
Forum: Grove
Topic: MQ2 Gas sensor Intro
Replies: 11
Views: 6163

Re: MQ2 Gas sensor Intro

In your code, you are reading the analog value and mapping it to 0 - 100 range. Please understand that this sensor's voltage range is non-linear. It also depends on the load resistor value (POT). It is better to use the analog value range 0 - 1023 to set gas detection threshold. If you intened to me...
by viswa
Wed Mar 02, 2016 8:24 pm
Forum: Grove
Topic: MQ2 Gas sensor Intro
Replies: 11
Views: 6163

Re: MQ2 Gas sensor Intro

Your code does not make use of the calculation that are already provided. If you are just looking for detection (i.e sense presense of a particular gas at a threshold), it might be useful.

Thanks and Warm Regards.
by viswa
Tue Mar 01, 2016 2:41 pm
Forum: LinkIt
Topic: LinkIt Smart 7688 Duo Poweroff problem
Replies: 5
Views: 10362

Re: LinkIt Smart 7688 Duo Poweroff problem

Hello,

Please use poweroff -h command to shutdown OpenWrt based systems. BTW, these OpenWrt systems are resilent to power-off.

Thanks and Warm Regards.
by viswa
Tue Mar 01, 2016 2:34 pm
Forum: Grove
Topic: MQ2 Gas sensor Intro
Replies: 11
Views: 6163

Re: MQ2 Gas sensor Intro

Hello, There is no recommended settings for Resistor POT. It depends on the sensitivity range required for your application. Please refer to MQ-2 datasheet for few pointers to set the Load Resistor value (i.e POT). If you are unsure, keeping the POT resistance at mid point would be sufficient for mo...
by viswa
Tue Mar 01, 2016 2:29 pm
Forum: Arduino & Seeeduino
Topic: CE Mark and EMC compliance
Replies: 1
Views: 1479

Re: CE Mark and EMC compliance

Hello,

Sorry. We do not have CE / EMC complaince certificates for Seeeduino.

Thanks and Warm Regards.
by viswa
Tue Mar 01, 2016 2:17 pm
Forum: Grove
Topic: is there a 5 pin grove connector?
Replies: 1
Views: 1264

Re: is there a 5 pin grove connector?

Hello,

The Grove standard only uses 4pin connector and cables. We do not have any 5 pin connector or cable.

Please search / look for JST connector & cables.

Thanks and Warm Regards
by viswa
Thu Feb 25, 2016 4:29 pm
Forum: Shields
Topic: LiPoRiderPro - Cope With High Open-Circuit Voltage ?
Replies: 2
Views: 2024

Re: LiPoRiderPro - Cope With High Open-Circuit Voltage ?

Found some discussion on similar topic here.