Clear Filters
Clear Filters

Arduino built in example "WriteMultipleFields" gets error code -301

9 views (last 30 days)
I am using an Arduino Uno R3 board and Ethernet shield. I replaced the Channel ID and the write API key with my own in the secrets.h file.
It connects with DHCP ok.
Arduino IDE 1.8.12
But comes back with error code -301. Serial Monitor:
Initialize Ethernet with DHCP:
DHCP assigned IP
Problem updating channel. HTTP error code -301
What am I missing?
Description: Writes values to fields 1,2,3 and 4 in a single ThingSpeak update every 20 seconds.
Hardware: Arduino Ethernet
!!! IMPORTANT - Modify the secrets.h file for this project with your network connection and ThingSpeak channel details. !!!
- Requires the Ethernet library
ThingSpeak ( ) is an analytic IoT platform service that allows you to aggregate, visualize, and
analyze live data streams in the cloud. Visit to sign up for a free account and create a channel.
Documentation for the ThingSpeak Communication Library for Arduino is in the folder where the library was installed.
See for the full ThingSpeak documentation.
For licensing information, see the accompanying license file.
Copyright 2018, The MathWorks, Inc.
#include "ThingSpeak.h"
#include <Ethernet.h>
#include "secrets.h"
byte mac[] = SECRET_MAC;
// Set the static IP address to use if the DHCP fails to assign
IPAddress ip(10, 10, 1, 76);
IPAddress myDns(10, 10, 1, 1);
EthernetClient client;
unsigned long myChannelNumber = SECRET_CH_ID;
const char * myWriteAPIKey = SECRET_WRITE_APIKEY;
// Initialize our values
int number1 = 0;
int number2 = random(0,100);
int number3 = random(0,100);
int number4 = random(0,100);
void setup() {
Ethernet.init(10); // Most Arduino Ethernet hardware
Serial.begin(115200); //Initialize serial
// start the Ethernet connection:
Serial.println("Initialize Ethernet with DHCP:");
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
// Check for Ethernet hardware present
if (Ethernet.hardwareStatus() == EthernetNoHardware) {
Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :(");
while (true) {
delay(1); // do nothing, no point running without Ethernet hardware
if (Ethernet.linkStatus() == LinkOFF) {
Serial.println("Ethernet cable is not connected.");
// try to congifure using IP address instead of DHCP:
Ethernet.begin(mac, ip, myDns);
} else {
Serial.print(" DHCP assigned IP ");
// give the Ethernet shield a second to initialize:
ThingSpeak.begin(client); // Initialize ThingSpeak
void loop() {
// set the fields with the values
ThingSpeak.setField(1, number1);
ThingSpeak.setField(2, number2);
ThingSpeak.setField(3, number3);
ThingSpeak.setField(4, number4);
// write to the ThingSpeak channel
int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
if(x == 200){
Serial.println("Channel update successful.");
Serial.println("Problem updating channel. HTTP error code " + String(x));
// change the values
if(number1 > 99){
number1 = 0;
number2 = random(0,100);
number3 = random(0,100);
number4 = random(0,100);
delay(20000); // Wait 20 seconds to update the channel again
Gerardo Spinelli
Gerardo Spinelli on 5 Nov 2020
I have the same problem with an Arduino MKR 1000. But in my case he issue is intermittent.

Sign in to comment.

Answers (2)

Vinod on 2 Aug 2020
Edited: Vinod on 2 Aug 2020
Have you made sure you're using the latest version of the library? Are you unable to see channel updates with the examples that ship with the library?

tebraxin tebraxin
tebraxin tebraxin on 7 Sep 2021
hello to everybody
i'm also using Arduino Uno with ethernet shield, and I still have error 301 with the example code (write multiple field)
I already read a lot of forum, questions etc.. all around internet but I still have the problem.
My network work cooretly with all my divecies,
I tried to change internal IP address, DNS IP address, cables, example codes form library Tingspeak... without solving the problem


More Answers in the  ThingSpeak Community


Find more on Read Data from Channel in Help Center and File Exchange


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!