Search found 11 matches

by pbanders
Sat Feb 16, 2019 12:39 am
Forum: Grove
Topic: Grove - Temperature&Humidity Sensor
Replies: 2
Views: 1138

Re: Grove - Temperature&Humidity Sensor

Are you using the "Pro" sensor, the one with the white sensor with the logo "AMSONG AM2302"? Be aware that this sensor has a 3.3K pull-down resistor that may be shunting the 3V3 supply on your Arduino board. I had this happen with a Stalker v3.1 I was using Try measuring the voltage on your 3V3 supp...
by pbanders
Sun Feb 03, 2019 6:26 am
Forum: Arduino & Seeeduino
Topic: Stalker v3.1: Question re: I2C selectable voltage
Replies: 3
Views: 1481

Re: Stalker v3.1: Question re: I2C selectable voltage

Thanks - maybe that's obvious to you that the level shifter handles this automatically, it isn't to me! When I read the VCC pins in the Grove sockets, I see 5V. I don't seem to have any 3.3V Grove devices, so I'll take your word for it. Thanks again for your reply.
by pbanders
Thu Jan 17, 2019 3:50 am
Forum: Arduino & Seeeduino
Topic: Stalker v3.1: Question re: I2C selectable voltage
Replies: 3
Views: 1481

Stalker v3.1: Question re: I2C selectable voltage

The Seeed product page for the Stalker v3.1 says:

"I2C Pin header (operation voltage is selectable: 5.0V or 3.3V)"

How is the voltage selectable? There's no switch or pad to disable the level shifter? Can this be done or is this spec in error?
by pbanders
Thu Jan 17, 2019 1:32 am
Forum: Arduino & Seeeduino
Topic: Stalker v3 : Limitations on using A4/A5 as inputs
Replies: 2
Views: 1034

Re: Stalker v3 : Limitations on using A4/A5 as inputs

A bit more on using A4/A5 on the Stalker v3 with INPUT_PULLUP. As I described, this works fine, but be aware that in the LOW state, that because of the I2C level shifter, you will be sinking significantly more pin current. In the LOW state on A4 or A5 defined as INPUT_PULLUP, the sink current is abo...
by pbanders
Wed Jan 16, 2019 12:02 pm
Forum: Grove
Topic: I2C and analog together?
Replies: 3
Views: 707

Re: I2C and analog together?

I think the problem you're having is that you're using A4/A5 for the analog input for the temp sensor, right? A4 and A5 are also SCL and SDA on the I2C bus, you can't be using them and I2C at the same time. Try switching to A0/A1 for the temperature sensor.
by pbanders
Tue Jan 15, 2019 11:22 pm
Forum: Arduino & Seeeduino
Topic: Stalker v3 : Limitations on using A4/A5 as inputs
Replies: 2
Views: 1034

Re: Stalker v3 : Limitations on using A4/A5 as inputs

Note that a workaround for using A4/A5 as inputs on the Stalker v3 is to define them in pinMode as INPUT_PULLUP. All that is required then is to connect the button switch between either A4/A5 and ground. In this mode, when the button is pressed, the pin state will be 0, when released, the pin state ...
by pbanders
Tue Jan 15, 2019 11:15 pm
Forum: Arduino & Seeeduino
Topic: Stalker v3: Replacing the RTC battery
Replies: 0
Views: 602

Stalker v3: Replacing the RTC battery

As many Stalker v3's are getting old, the RTC batteries may need to be replaced. First, measure the battery voltage to determine if replacement is needed, the nominal voltage for the CR1220 cell is 3 V, but the RTC may continue to be backed-up even if the cell voltage is 2.75 V or less. If replaceme...
by pbanders
Tue Jan 15, 2019 5:51 am
Forum: Arduino & Seeeduino
Topic: Cannot get Seeeduino V4.2 to show up in device manager
Replies: 3
Views: 1504

Re: Cannot get Seeeduino V4.2 to show up in device manager

Also notice on the wiki page that if you want the v4.2 to show up in the boards list in the Arduino IDE, you have to add the location of the file to the list of board file locations in Preferences.
by pbanders
Tue Jan 15, 2019 5:35 am
Forum: Arduino & Seeeduino
Topic: Cannot get Seeeduino V4.2 to show up in device manager
Replies: 3
Views: 1504

Re: Cannot get Seeeduino V4.2 to show up in device manager

Start up Device Manager. Look under "Ports", do you see any new COM port entry? That's your Seeeduino v4.2 board. Windows won't find a driver for it, you have to go to the wiki page for the v4.2 and download the driver, then install it manually. Be aware that many Windows 10 machines won't allow you...
by pbanders
Mon Jan 14, 2019 9:49 pm
Forum: Arduino & Seeeduino
Topic: Stalker v3 : Limitations on using A4/A5 as inputs
Replies: 2
Views: 1034

Stalker v3 : Limitations on using A4/A5 as inputs

Be aware that on the Stalker v3 that since A4 and A5 are also used for the I2C bus (SDA/SCL), and that the I2C bus uses a level translator for 5V operation, that if you specify A4 or A5 as INPUT in pinMode, they will be pulled-up to 3.3 V. Even using a 10K pull-down will only bring the pin voltage d...