More Wireless (2)

weirdwave1Figure 1: More Wireless Waves

I’ve also been eyeing the JY-MCU HC05 Bluetooth boards, available online for less than five bucks each.  They’re not 100 milliwatt units though, so they might be as much of a challenge as the nRF24 devices.  A hundred milliwatt bluetooth board would have a range of about 300 feet, but would be a much more serious drain on the batteries, which I’m trying to avoid.  I think I’ll be able to make the nRF24 devices play well enough, but am always looking for second options when I can find them.

Here is info about fixing the Odroid/C1 SPI issue using device tree instead of external hardware (resistors on p19 and p23):

Per this odroid forum post:

http://forum.odroid.com/viewtopic.php?f=117&t=21595

The device tree can be modified thusly to effect the “pull down” of SCL:


aml_spicc_pins: aml_spicc_pins{
       amlogic,setmask=<4 0x03c00000>;
       amlogic,clrmask=<3 0x004003C0
            5 0x00000C00
            6 0x000F0000
            7 0x80000000
            8 0x00000003
            9 0x00080000>;
       amlogic,pins = "GPIOX_8","GPIOX_9","GPIOX_10";
amlogic,pullup=<0>;
amlogic,pullupen=<1>;

This mod was provided on the odroid forum by CrashOverride. I haven’t yet checked it out, to see if my nRF24 devices will play without the external resistors, using this fix.

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Note: the author does not have a recent, applicable background in circuit building, or battery related issues, so this is presented as the work of a hobbyist, and is not meant for duplication by others. Readers should look elsewhere for design advice and info.

Note: The Odroid site is http://www.hardkernel.com and is not affiliated with this site in any way. The nrf24 is a product of https://www.nordicsemi.com, and they are not affiliated with this author or website in any way. The Trinket is a product of Adafruit at adafruit.com.  This site and author has no affiliation with Adafruit. Bluetooth is a trademark of the Bluetooth Special Interest Group, and is not affiliated with this author or site in any way.

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