PU2CLR AKC695X Arduino Library  1.0.1
This is an Arduino Library to control the AKC695X / M695X DSP radio devices
PU2CLR AKC695X Arduino Library

this library is under construction.....

ATTENTION: This library is under construction. Some functions may not work as expected!

This is an Arduino Library to control the AKC695X / M695X DSP radio devices.

This library can be freely distributed using the MIT Free Software model.

Copyright (c) 2020 Ricardo Lima Caratti.

Contact: __pu2.nosp@m.clr@.nosp@m.gmail.nosp@m..com.nosp@m.__.

Contents

  1. [Preface]()
  2. MIT License
  3. About AKC695X / M695X DSP radio
  4. AKC695X Pin definitions
  5. Schematic
  6. API Documentation

Preface

MIT License

Copyright (c) 2019 Ricardo Lima Caratti

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE ARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

About AKC695X / M695X DSP radio

The AKC695X is a family of IC DSP receiver from AKC technology. The AKC6955 and AKC6959 support AM and FM modes. On AM mode the AKC6955 and AKC6969 work on LW, MW and SW. On FM mode they work from 64MHz to 222MHz.

AKC695X features

The table below shows some features fo the AKC695X devices family.

Feature AKC6951 AKC6955 AKC6959
stand by 30 ~ 230MHz Any frequency FM demodulation X X X
stand by 0.15 ~ 30MHz Any frequency AM demodulation X X X
Preset FM band ( 64 ~ 108 MHz ) X X X
stand by TV1 audio( 56.25 ~ 91.75 MHz ) X X X
stand by TV2 audio( 174.75 ~ 222.25 MHz ) X X X
Presets wave band ( 520 ~ 1730 KHz ) X X X
Preset shortwave band ( 3.2 ~ 21.9 MHz ) X X
Preset long-wave band ( 150 ~ 285 KHz ) X X X
Custom support band X X X
It supports a wide supply voltage range: 2.0V ~ 4.5V X X X
stand by 32.768KHz & 12MHz Passive mode crystal reference clock and Pin X X X
Integrated audio amplifier (maximum power differential 0.5W ) X X X
Two kinds of control volume: volume potentiometer and the volume register X X X
Two kinds of de-emphasis modes: 50us / 75us X X X
Support tuning lamp function X X X
The audio output may be in phase, may be inverted output X X X
Support for stereo line input X X X
Support low-power standby mode, 3V When power consumption 10uA X X X
Internal integrated PLL X X X
Intelligent frequency control X X X
AGC X X X
Precise digital demodulation X X X
Smart mute function X X X
SW Increased tracking filter, greatly improving SW Audibility X X
MW Precise tuning adaptive front end X X X
FM Subwoofer X X X
integrated LDO X X X
According to the battery voltage, automatically adjust the volume X X X
Pb-free / RoHS complian X X X

Sources: AKC6951, AKC6955 and AKC6959 Datasheets.

Registers setup

Table Reg1

Reg1: configure register 1 (default: 0x10) Address - Type 0x01 (RW)

BIT Label Default Function Description
7:3 amband 0x2 see table [Table Reg1 amband]()
2:0 fmband 0x00 see table [Table Reg1 fmband]()

Band seek logic chip only valid for tune logic, frequency can be adjusted at any stage

Table Reg1 amband

The table below can help you to select the right band and its frequency limits. You might need to use it in your Arduino sketch.

amband value N# Description
00000 0 LW, 0.15 ~ 0.285, 3K station search
00001 1 MW1, 0.52 ~ 1.71, 5K station search
00010 2 MW2, 0.522 ~ 1.62, 9K station search
00011 3 MW3, 0.52 ~ 1.71, 10K station search
00100 4 SW1, 4.7 ~ 10, 5K station search
00101 5 SW2, 3.2 ~ 4.1, 5K station search
00110 6 SW3, 4.7 ~ 5.6, 5K station search
00111 7 SW4, 5.7 ~ 6.4, 5K station search
01000 8 SW5, 6.8 ~ 7.6, 5K station search
01001 9 SW6, 9.2 ~ 10, 5K station search
01010 10 SW7, 11.4 ~ 12.2, 5K station search
01011 11 SW8, 13.5 ~ 14.3
01100 12 SW9, 15 ~ 15.9
01101 13 SW10, 17.4 ~ 17.9
01110 14 SW11, 18.9 ~ 19.7, 5K station search
01111 15 SW12, 21.4 ~ 21.9, 5K station search
10000 16 SW13, 11.4 ~ 17.9, 5K station search
10010 17 MW4, 0.52 to 1.73, 5K station search
Other 18+ custom band, station search interval = 3K

Table Reg1 fmband

fmband value N# Description
000 0 FM1,87 ~ 108, station search space specified intervals
001 1 FM2,76 ~ 108, station search space specified intervals
010 2 FM3,70 ~ 93, with a space station search interval set
011 3 FM4,76 ~ 90, Tuning predetermined space intervals
100 4 FM5,64 ~ 88, with a space station search interval set
101 5 TV1,56.25 ~ 91.75, station search space specified intervals
110 6 TV2, 174.75 ~ 222.25, found
111 7 sets predetermined space intervals, custom FM, station search space specified intervals

Table Reg2 and Reg3

The registers 2 and 3 are used together. The tuning frequency is obtained by calculation. The formula is described below.

Reg2

BIT Label Default Function Description
7 rsv 0 Reserved for internal use.
6 ref_32k_mo 1 1 = 32.768 crystal; 0 = 12MHz crystal
5 Mode3k 0 1 = 3K custom channel number as the AM mode; 0 = custom channel number pattern 5K
4:0 Channel 0x0A The higher 5 bits of the channel number. See comments [ˆ1] and [ˆ2]

Reg3

BIT Label Default Function Description
7:0 rsv 0xC8 The lower 8 bits of the channel number. See comment [ˆ1]

[ˆ1]

  1. On FM mode: Channel Freq = 25kHz * CHAN + 30MHz;
  2. On AM mode:
    • when 5K channel number pattern, Channel Freq = 5kHz * CHAN
    • when 3K channel number pattern, Channel Freq = 3kHz * CHAN.

[ˆ2] If the MCU is working with MW2 (see table Table Reg1 amband), the channel number has to be a multiple of three. Otherwise, the radio will be a mess.

Schematic

The figure below shows the basic schematic of the AKC695X and Arduino Pro Mini 3.3V, 8MHz.

Basic Schematic

AKC695X Pin definitions

The figure and table below show the pin description of the AKC6951 and AKC6955.

AKC6951(55) pin out

Pin Name Description
1 oscin Bonding or passive 32.768K 12MHz crystal to ground, or receive an external clock reference signal
2 oscout Passive other end connected to the crystal, when connected to an external clock, this pin floating
3 gnd Close to ground
4 tund Radio lock indicator pin, connected directly to the light emitting diode; Tuning the MCU software when the pin may also be used as a stop sign
5 p_on On-chip power switch, high input power chip; the chip down in a low-power standby state, power consumption of approximately 10uA
6 sclk 2C clock signal input
7 sdio I2C bidirectional data signal input / output
8 inl External audio signal input L, proposes to add blocking capacitor 1uF
9 inr External audio input signal R, proposes to add blocking capacitor 1uF
10 vbat Then the power pins need to pay attention to the nearest ground 0.1uF decoupling capacitance to ground
11 lout Left channel audio output
12 gnd gnd
13 rout Right channel audio output
14 vref Precision 1.5V output pin, to provide a baseline volume potentiometer
15 vol Variable volume potentiometer connected end, the fixed end of a potentiometer directly connected to VREF, and the other end through a resistor to ground. The resistance ratio of the resistor and potentiometer as 1: 2
16 vbat Then the power pins need to pay attention to the nearest ground 0.1uF decoupling capacitance to ground
17 gnd Close to ground
18 mwinN MW and LW differential input signal
19 mwinP MW and LW differential input signal
20 swin Shortwave signal input terminal, note add blocking capacitor recommended 3nF
21 gnd Close to ground
22 fmin FM radio frequency signal input terminal, note add blocking capacitor, 100pF recommendations
23 ldocap Internal LDO output pin, nearest the need decoupling capacitors, recommendations 47uF
24 gnd Close to ground

Receivers based on

References