This document is an inventory for the messages used between the backend and the farmbot.
The farmbot hardware communicates with the backend trough the skynet protocol, a machine instant messaging protocol. All information is packaged as JSON. A typical message in skynet looks like this:
{
"devices"=>"44128811-8c59-11e3-b99a-11476114e05f",
"message"=>
{
"message_type"=>"confirmation",
"time_stamp"=>"1403894016.000322"
},
"fromUuid"=>"68591ebf-d354-4a3a-8b83-0453bf4e8b23"
}
Everything in the message variable is custom. Skynet itself will always use create the device, message and fromUuid variable.
For farmbot, two elements are always present in the message:
| variable | example value | description |
|---|---|---|
| message_type | single_command | the type of message |
| time_stamp | 1403805036.4898174 | a string value to make the message unique |
The message type is a string that defines what the message does. Current available message types are:
| send by backend | response by farmbot |
|---|---|
| single_command | confirmation |
| read_parameters | read_parameters_response |
| read_status | read_status_response |
| read_logs | read_logs_response |
| write_parameters | confirmation |
| crop_schedule_update | confirmation |
Some messages get a short response as a confirmation from the farmbot that the message is read and processed. The farmbot puts into 'confirm_id' the 'time_stamp' of the message that is processed.
{
"message_type"=>"confirmation",
"time_stamp"=>"1403894016.000322",
"confirm_id"=>"1403894021.7605221"
}
To move the farmbot manually, a message is send with type 'single command'. The farmbot will put the command into the schedule for immediate execution. The message looks like:
{
:message_type=>"single_command",
:time_stamp=>"1403805036.4898174",
:command=>
{
:action=>"MOVE RELATIVE",
:x=>0,
:y=>10,
:z=>0,
:speed=>"manouvering",
:amount=>0,
:delay=>0
}
}
| variable | type | desciption |
|---|---|---|
| action | string | the action/movement to do |
| x | decimal | in absolute mode, the new place to move to. in relative mode, the amount to move, in millimeter |
| y | decimal | same as x |
| z | decimal | same as x |
| speed | string | speed for movements, as text. for example 'traveling', 'manouvering' |
| amount | decimal | amount of mililiter of water to dose. always add parameter with default value |
| delay | decimal | amount in seconds to delay the execution of a command |
| pin_nr | decimal | the number of the pin to change or pin for servo, using arduino numbering |
| pin_value1 | decimal | the value for the pin, for servo movement the angle |
| pin_value2 | decimal | when using a pulse, this is the value for the second flank of the pulse |
| pin_mode | decimal | for setting the I/O mode, 0 is input, 1 is output. For reading and writing, 0 is digital and 1 is analog |
| pin_time | decimal |
actions and parameters used:
| action | x | y | z | speed | amount | delay | pin_nr | pin_value1 | pin_value2 | pin_mode | pin_time |
|---|---|---|---|---|---|---|---|---|---|---|---|
| MOVE RELATIVE | X | X | X | X | X | ||||||
| MOVE ABSOLUTE | X | X | X | X | X | ||||||
| DOSE WATER | X | X | |||||||||
| HOME X | X | X | |||||||||
| HOME Y | X | X | |||||||||
| HOME Z | X | X | |||||||||
| PIN WRITE | X | X | X | X | |||||||
| PIN READ | X | X | X | ||||||||
| PIN MODE | X | X | X | ||||||||
| PIN PULSE | X | X | X | X | X | X | |||||
| SERVO MOVE | X | X | X |
{
:message_type => "read_status",
:time_stamp => "1403818238.3181107"
}
{
"message_type" => "read_status_return",
"time_stamp" => "1403818234.1559582",
"confirm_id" => "1403818238.3181107",
"status" => "no command found, waiting",
"status_time_local" => "2014/06/26 20:30:34 -0100",
"status_nr_msg_received" => 7,
"status_movement" => "idle",
"status_last_command_executed" => "2014/06/26 20:05:08 -0100",
"status_next_command_scheduled" => nil,
"status_nr_of_commands_executed" => 1,
"status_current_x" => 10,
"status_current_y" => 20,
"status_current_z" => 30,
"status_target_x" => 40,
"status_target_y" => 50,
"status_target_z" => 60,
"status_end_stop_x_a" => true,
"status_end_stop_x_b" => false,
"status_end_stop_y_a" => true,
"status_end_stop_y_b" => false,
"status_end_stop_z_a" => true,
"status_end_stop_z_b" => false
}
Sending the read log command to the farmbot and it will reply with a list of all recent logs
{
:message_type => "read_logs",
:time_stamp => "1403805653.5407457"
}
{
"devices"=>"44128811-8c59-11e3-b99a-11476114e05f",
"message"=>
{
"message_type"=>"read_parameters_response",
"time_stamp"=>"1403820163.8032863",
"confirm_id"=>"1403820168.4028015",
"logs"=>
[
{"text"=>"Controller running", "module"=>1, "time"=>"2014/06/26 21:01:11 -0100"},
{"text"=>"sender 44128811-8c59-11e3-b99a-11476114e05f", "module"=>2, "time"=>"2014/06/26 21:01:21 -0100"},
{"text"=>"message_type = single_command", "module"=>2, "time"=>"2014/06/26 21:01:21 -0100"},
{"text"=>"handle single command", "module"=>2, "time"=>"2014/06/26 21:01:21 -0100"},
{"text"=>"sender = 44128811-8c59-11e3-b99a-11476114e05f", "module"=>2, "time"=>"2014/06/26 21:01:21 -0100"},
{"text"=>"[MOVE RELATIVE] x: 0, y: 10, z: 0, speed: 0, amount: 0 delay: 0", "module"=>2, "time"=>"2014/06/26 21:01:21 -0100"},
{"text"=>"[SIM] move relative xyz=0.0 10.0 0.0 amt=0.0 spd=0", "module"=>1, "time"=>"2014/06/26 21:01:23 -0100"},
{"text"=>"sending comfirmation", "module"=>2, "time"=>"2014/06/26 21:01:23 -0100"},
{"text"=>"done", "module"=>2, "time"=>"2014/06/26 21:01:24 -0100"}
]
}
}
The list of parameters in the system when using a RAMPS system:
| parameter | type | unit of measurement |
|---|---|---|
| ramps_move_home_timeout_x | 1 | millimeter |
| ramps_move_home_timeout_y | 1 | millimeter |
| ramps_move_home_timeout_z | 1 | millimeter |
| ramps_invert_axis_x | 4 | 0/1 |
| ramps_invert_axis_y | 4 | 0/1 |
| ramps_invert_axis_z | 4 | 0/1 |
| ramps_steps_per_unit_x | 1 | millimeter |
| ramps_steps_per_unit_y | 1 | millimeter |
| ramps_steps_per_unit_z | 1 | millimeter |
| ramps_pos_max_x | 1 | millimeter |
| ramps_pos_max_y | 1 | millimeter |
| ramps_pos_max_z | 1 | millimeter |
| ramps_pos_min_x | 1 | millimeter |
| ramps_pos_min_y | 1 | millimeter |
| ramps_pos_min_z | 1 | millimeter |
| ramps_reverse_home_x | 4 | 0/1 |
| ramps_reverse_home_y | 4 | 0/1 |
| ramps_reverse_home_z | 4 | 0/1 |
The type id number used for storing in sqlite
| id | type |
|---|---|
| 1 | integer |
| 2 | float |
| 3 | string |
| 4 | boolean |
If you send a message for reading the parameters, farmbot will reply with a list of all parameters present in the system. The list of parameters are created at the first boot of the system.
{
:message_type=>"read_parameters",
:time_stamp=>"1403816116.954407"
}
{
"message_type"=>"read_parameters_response",
"time_stamp"=>"1403816112.8748097",
"confirm_id"=>"1403816116.954407",
"parameters"=>
[
{"name"=>"ramps_move_home_timeout_x", "type"=>1, "value"=>31},
{"name"=>"ramps_move_home_timeout_y", "type"=>1, "value"=>32},
{"name"=>"ramps_move_home_timeout_z", "type"=>1, "value"=>33}
]
}
This message is used to send a list of the values that need to be changed to the farmbot. It will reply with a simple confirmation
{
:message_type=>"write_parameters",
:time_stamp=>"1403812040.7974331",
:parameters=>
[
{:name=>"ramps_move_home_timeout_x", :type=>1, :value=>30},
{:name=>"ramps_move_home_timeout_y", :type=>1, :value=>35},
{:name=>"ramps_move_home_timeout_z", :type=>1, :value=>40}
]
}