Search found 96 matches

by fredbox
Sun Aug 02, 2015 10:57 pm
Forum: Libraries & Hardware
Topic: I2C clock speed for Maple Mini
Replies: 2
Views: 1351

I2C clock speed for Maple Mini

There are some discussions in some other threads about setting the I2C clock rate. I did some experimenting on my BAITE Maple Mini clone and checked with a logic analyzer clone. The tests were reads of 16 bytes blocks from a device and taking the fastest consistent clock rate. Using Hardwire: #inclu...
by fredbox
Fri Jul 24, 2015 2:40 am
Forum: Projects
Topic: Open Energy Monitor
Replies: 65
Views: 9430

Re: Open Energy Monitor

Hi Roger, You've made a couple of references to 3 volts. I hope you mean peak-to-peak and not rms. 1 volt rms (2.8V p-p) would be about optimum for feeding the analog input on a 3.3 volt processor. The zero crossing point should be offset from ground to half the supply voltage, or 1.65 vdc. Otherwis...
by fredbox
Mon Jul 13, 2015 1:10 am
Forum: Hardware
Topic: RDA5807M FM Radio on Maple Mini [Solved]
Replies: 8
Views: 2454

Re: RDA5807M FM Radio on Maple Mini [Solved]

It turns out the problem was on my end, so I am marking this solved. I realized while I was reviewing Ray's I2C code for the BMP180 that he wasn't calling any other wire function after Wire.requestFrom other than Wire.available(). Wire.endTransmission() sends the contents of the buffer to the device...
by fredbox
Sun Jul 12, 2015 1:33 am
Forum: Hardware
Topic: RDA5807M FM Radio on Maple Mini [Solved]
Replies: 8
Views: 2454

Re: RDA5807M FM Radio on Maple Mini

I took victor_pv's suggestion to add delays and also set up a debug pin that would go high before the function call and low afterwards. Wire.requestFrom() toggles the SDA/SCL lines and appears as a read command followed by the data. Wire.read() must be reading the internal buffer, as there is no act...
by fredbox
Sat Jul 11, 2015 5:33 pm
Forum: Hardware
Topic: RDA5807M FM Radio on Maple Mini [Solved]
Replies: 8
Views: 2454

Re: RDA5807M FM Radio on Maple Mini

I'm using 2.2K pullup resistors. i2c scanner detects devices at 0x10, 0x11, and 0x60. This is correct. The frequency using Wire is about 350khz. Twowire with SOFT_STANDARD is just over 100khz. Hardwire is 400khz. All three methods show the extra write to the read address. I'm still looking for the c...
by fredbox
Sat Jul 11, 2015 4:25 am
Forum: Hardware
Topic: RDA5807M FM Radio on Maple Mini [Solved]
Replies: 8
Views: 2454

RDA5807M FM Radio on Maple Mini [Solved]

I'm attempting to use i2C to access the registers on one of the RDA5807 FM radio modules that are available on eBay. I have two wired on a breadboard, with a Maple Mini on one end and a Arduino Nano on the other. The Arduino communicates without any problem, but the Maple Mini doesn't work. I'm seei...