A detailed article about Chokhamela is available at http://www.spiritual-note.com/Sant_Chokhamela
Chokhamela lived in Mangalavedha near Pandharpur in Maharashtra in the 14th century. He was born in the lower cast (Mahar), but his devotion to Lord Vitthala was pure and unmatched. He migrated to Pandharpur and became a desciple of the great saint-poet Namdev. Chokha used to constantly chant the name of Panduranga and clean the temple premises daily. However, he was not allowed to enter the sanctum sanctorum due to his birth in the lower cast. One day someone questioned the futility of his devotion to Lord, as he would never be able to see God. Humiliated and deeply hurt Chokha abstained from taking food and wept inconsolably when Panduranga appeared before him, embraced him, took him inside the temple and talked to him. The temple priest was outraged as he felt that the temple was desecreted by Chokha and ordered him to stay across the river Chandrabhaga. Chokha's pleas fell on the deaf ears and at last Chokha went to stay across the river. However, Lord started to visit Chokha daily and both of them used to take lunch together. One day the priest was passing by Chokha's hut when Chokha was taking lunch with Panduranga and Soyara (Chokha's wife) was serving. Priest could not see Panduranga as his mind was impure. Soyara spilled the curd on Panduranga's pitambar by mistake. Chokha exclaimed, "Oh! Soyara you have soiled Panduranga's pitambar". Priest felt it was a deliberate attempt by Chokha to show his devotion and slapped Chokha across his face. Later he bathed in the river and ferried across the river. The priest was stunned to see Lord Vitthala's swollen cheek. He realised the intensity of Chokha's devotion towards Lord. He to Chokha, asked for his forgiveness and requested him to pacify the Lord. Chokha's prayers and request pacified Lord Vitthala.
Chokha was forced to return to Mangalavedha as the people there wanted to construct a wall in order to separate shudra people from others. While he was working there, he was killed when the wall collapsed and was crushed. Namdev deeply grieved the death of a great Vaishnava devotee, went to Mangalavedha and brought the mortal remains to Chokha and constructed his Samadhi in Pandharpur.